creation_sourcecode: // File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC721/IERC721Receiver.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @title ERC721 token receiver interface
   * @dev Interface for any contract that wants to support safeTransfers
   * from ERC721 asset contracts.
   */
  interface IERC721Receiver {
      /**
       * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
       * by `operator` from `from`, this function is called.
       *
       * It must return its Solidity selector to confirm the token transfer.
       * If any other value is returned or the interface is not implemented by the recipient, the transfer will be
       * reverted.
       *
       * The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.
       */
      function onERC721Received(
          address operator,
          address from,
          uint256 tokenId,
          bytes calldata data
      ) external returns (bytes4);
  }
  
  // File: contracts/IERC721A.sol
  
  
  // ERC721A Contracts v4.1.0
  // Creator: Chiru Labs
  
  pragma solidity ^0.8.4;
  
  /**
   * @dev Interface of an ERC721A compliant contract.
   */
  
  
  interface IERC721A {
      /**
       * The caller must own the token or be an approved operator.
       */
      error ApprovalCallerNotOwnerNorApproved();
  
      /**
       * The token does not exist.
       */
      error ApprovalQueryForNonexistentToken();
  
      /**
       * The caller cannot approve to their own address.
       */
      error ApproveToCaller();
  
      /**
       * Cannot query the balance for the zero address.
       */
      error BalanceQueryForZeroAddress();
  
      /**
       * Cannot mint to the zero address.
       */
      error MintToZeroAddress();
  
      /**
       * The quantity of tokens minted must be more than zero.
       */
      error MintZeroQuantity();
  
      /**
       * The token does not exist.
       */
      error OwnerQueryForNonexistentToken();
  
      /**
       * The caller must own the token or be an approved operator.
       */
      error TransferCallerNotOwnerNorApproved();
  
      /**
       * The token must be owned by `from`.
       */
      error TransferFromIncorrectOwner();
  
      /**
       * Cannot safely transfer to a contract that does not implement the ERC721Receiver interface.
       */
      error TransferToNonERC721ReceiverImplementer();
  
      /**
       * Cannot transfer to the zero address.
       */
      error TransferToZeroAddress();
  
      /**
       * The token does not exist.
       */
      error URIQueryForNonexistentToken();
  
      /**
       * The `quantity` minted with ERC2309 exceeds the safety limit.
       */
      error MintERC2309QuantityExceedsLimit();
  
      /**
       * The `extraData` cannot be set on an unintialized ownership slot.
       */
      error OwnershipNotInitializedForExtraData();
  
      struct TokenOwnership {
          // The address of the owner.
          address addr;
          // Keeps track of the start time of ownership with minimal overhead for tokenomics.
          uint64 startTimestamp;
          // Whether the token has been burned.
          bool burned;
          // Arbitrary data similar to `startTimestamp` that can be set through `_extraData`.
          uint24 extraData;
      }
  
      /**
       * @dev Returns the total amount of tokens stored by the contract.
       *
       * Burned tokens are calculated here, use `_totalMinted()` if you want to count just minted tokens.
       */
      function totalSupply() external view returns (uint256);
  
      // ==============================
      //            IERC165
      // ==============================
  
      /**
       * @dev Returns true if this contract implements the interface defined by
       * `interfaceId`. See the corresponding
       * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
       * to learn more about how these ids are created.
       *
       * This function call must use less than 30 000 gas.
       */
      function supportsInterface(bytes4 interfaceId) external view returns (bool);
  
      // ==============================
      //            IERC721
      // ==============================
  
      /**
       * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
       */
      event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
  
      /**
       * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
       */
      event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
  
      /**
       * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
       */
      event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
  
      /**
       * @dev Returns the number of tokens in ``owner``'s account.
       */
      function balanceOf(address owner) external view returns (uint256 balance);
  
      /**
       * @dev Returns the owner of the `tokenId` token.
       *
       * Requirements:
       *
       * - `tokenId` must exist.
       */
      function ownerOf(uint256 tokenId) external view returns (address owner);
  
      /**
       * @dev Safely transfers `tokenId` token from `from` to `to`.
       *
       * Requirements:
       *
       * - `from` cannot be the zero address.
       * - `to` cannot be the zero address.
       * - `tokenId` token must exist and be owned by `from`.
       * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
       * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
       *
       * Emits a {Transfer} event.
       */
      function safeTransferFrom(
          address from,
          address to,
          uint256 tokenId,
          bytes calldata data
      ) external;
  
      /**
       * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
       * are aware of the ERC721 protocol to prevent tokens from being forever locked.
       *
       * Requirements:
       *
       * - `from` cannot be the zero address.
       * - `to` cannot be the zero address.
       * - `tokenId` token must exist and be owned by `from`.
       * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
       * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
       *
       * Emits a {Transfer} event.
       */
      function safeTransferFrom(
          address from,
          address to,
          uint256 tokenId
      ) external;
  
      /**
       * @dev Transfers `tokenId` token from `from` to `to`.
       *
       * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
       *
       * Requirements:
       *
       * - `from` cannot be the zero address.
       * - `to` cannot be the zero address.
       * - `tokenId` token must be owned by `from`.
       * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
       *
       * Emits a {Transfer} event.
       */
      function transferFrom(
          address from,
          address to,
          uint256 tokenId
      ) external;
  
      /**
       * @dev Gives permission to `to` to transfer `tokenId` token to another account.
       * The approval is cleared when the token is transferred.
       *
       * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
       *
       * Requirements:
       *
       * - The caller must own the token or be an approved operator.
       * - `tokenId` must exist.
       *
       * Emits an {Approval} event.
       */
      function approve(address to, uint256 tokenId) external;
  
      /**
       * @dev Approve or remove `operator` as an operator for the caller.
       * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
       *
       * Requirements:
       *
       * - The `operator` cannot be the caller.
       *
       * Emits an {ApprovalForAll} event.
       */
      function setApprovalForAll(address operator, bool _approved) external;
  
      /**
       * @dev Returns the account approved for `tokenId` token.
       *
       * Requirements:
       *
       * - `tokenId` must exist.
       */
      function getApproved(uint256 tokenId) external view returns (address operator);
  
      /**
       * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
       *
       * See {setApprovalForAll}
       */
      function isApprovedForAll(address owner, address operator) external view returns (bool);
  
      // ==============================
      //        IERC721Metadata
      // ==============================
  
      /**
       * @dev Returns the token collection name.
       */
      function name() external view returns (string memory);
  
      /**
       * @dev Returns the token collection symbol.
       */
      function symbol() external view returns (string memory);
  
      /**
       * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
       */
      function tokenURI(uint256 tokenId) external view returns (string memory);
  
      // ==============================
      //            IERC2309
      // ==============================
  
      /**
       * @dev Emitted when tokens in `fromTokenId` to `toTokenId` (inclusive) is transferred from `from` to `to`,
       * as defined in the ERC2309 standard. See `_mintERC2309` for more details.
       */
      event ConsecutiveTransfer(uint256 indexed fromTokenId, uint256 toTokenId, address indexed from, address indexed to);
  }
  // File: contracts/ERC721A.sol
  
  
  // ERC721A Contracts v4.1.0
  // Creator: Chiru Labs
  
  pragma solidity ^0.8.4;
  
  
  /**
   * @dev ERC721 token receiver interface.
   */
  interface ERC721A__IERC721Receiver {
      function onERC721Received(
          address operator,
          address from,
          uint256 tokenId,
          bytes calldata data
      ) external returns (bytes4);
  }
  
  /**
   * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard,
   * including the Metadata extension. Built to optimize for lower gas during batch mints.
   *
   * Assumes serials are sequentially minted starting at `_startTokenId()`
   * (defaults to 0, e.g. 0, 1, 2, 3..).
   *
   * Assumes that an owner cannot have more than 2**64 - 1 (max value of uint64) of supply.
   *
   * Assumes that the maximum token id cannot exceed 2**256 - 1 (max value of uint256).
   */
  contract ERC721A is IERC721A {
      // Mask of an entry in packed address data.
      uint256 private constant BITMASK_ADDRESS_DATA_ENTRY = (1 << 64) - 1;
  
      // The bit position of `numberMinted` in packed address data.
      uint256 private constant BITPOS_NUMBER_MINTED = 64;
  
      // The bit position of `numberBurned` in packed address data.
      uint256 private constant BITPOS_NUMBER_BURNED = 128;
  
      // The bit position of `aux` in packed address data.
      uint256 private constant BITPOS_AUX = 192;
  
      // Mask of all 256 bits in packed address data except the 64 bits for `aux`.
      uint256 private constant BITMASK_AUX_COMPLEMENT = (1 << 192) - 1;
  
      // The bit position of `startTimestamp` in packed ownership.
      uint256 private constant BITPOS_START_TIMESTAMP = 160;
  
      // The bit mask of the `burned` bit in packed ownership.
      uint256 private constant BITMASK_BURNED = 1 << 224;
  
      // The bit position of the `nextInitialized` bit in packed ownership.
      uint256 private constant BITPOS_NEXT_INITIALIZED = 225;
  
      // The bit mask of the `nextInitialized` bit in packed ownership.
      uint256 private constant BITMASK_NEXT_INITIALIZED = 1 << 225;
  
      // The bit position of `extraData` in packed ownership.
      uint256 private constant BITPOS_EXTRA_DATA = 232;
  
      // Mask of all 256 bits in a packed ownership except the 24 bits for `extraData`.
      uint256 private constant BITMASK_EXTRA_DATA_COMPLEMENT = (1 << 232) - 1;
  
      // The mask of the lower 160 bits for addresses.
      uint256 private constant BITMASK_ADDRESS = (1 << 160) - 1;
  
      // The maximum `quantity` that can be minted with `_mintERC2309`.
      // This limit is to prevent overflows on the address data entries.
      // For a limit of 5000, a total of 3.689e15 calls to `_mintERC2309`
      // is required to cause an overflow, which is unrealistic.
      uint256 private constant MAX_MINT_ERC2309_QUANTITY_LIMIT = 5000;
  
      // The tokenId of the next token to be minted.
      uint256 private _currentIndex;
  
      // The number of tokens burned.
      uint256 private _burnCounter;
  
      // Token name
      string private _name;
  
      // Token symbol
      string private _symbol;
  
      // Mapping from token ID to ownership details
      // An empty struct value does not necessarily mean the token is unowned.
      // See `_packedOwnershipOf` implementation for details.
      //
      // Bits Layout:
      // - [0..159]   `addr`
      // - [160..223] `startTimestamp`
      // - [224]      `burned`
      // - [225]      `nextInitialized`
      // - [232..255] `extraData`
      mapping(uint256 => uint256) private _packedOwnerships;
  
      // Mapping owner address to address data.
      //
      // Bits Layout:
      // - [0..63]    `balance`
      // - [64..127]  `numberMinted`
      // - [128..191] `numberBurned`
      // - [192..255] `aux`
      mapping(address => uint256) private _packedAddressData;
  
      // Mapping from token ID to approved address.
      mapping(uint256 => address) private _tokenApprovals;
  
      // Mapping from owner to operator approvals
      mapping(address => mapping(address => bool)) private _operatorApprovals;
  
      constructor(string memory name_, string memory symbol_) {
          _name = name_;
          _symbol = symbol_;
          _currentIndex = _startTokenId();
      }
  
      /**
       * @dev Returns the starting token ID.
       * To change the starting token ID, please override this function.
       */
      function _startTokenId() internal view virtual returns (uint256) {
          return 1;
      }
  
      /**
       * @dev Returns the next token ID to be minted.
       */
      function _nextTokenId() internal view returns (uint256) {
          return _currentIndex;
      }
  
      /**
       * @dev Returns the total number of tokens in existence.
       * Burned tokens will reduce the count.
       * To get the total number of tokens minted, please see `_totalMinted`.
       */
      function totalSupply() public view override returns (uint256) {
          // Counter underflow is impossible as _burnCounter cannot be incremented
          // more than `_currentIndex - _startTokenId()` times.
          unchecked {
              return _currentIndex - _burnCounter - _startTokenId();
          }
      }
  
      /**
       * @dev Returns the total amount of tokens minted in the contract.
       */
      function _totalMinted() internal view returns (uint256) {
          // Counter underflow is impossible as _currentIndex does not decrement,
          // and it is initialized to `_startTokenId()`
          unchecked {
              return _currentIndex - _startTokenId();
          }
      }
  
      /**
       * @dev Returns the total number of tokens burned.
       */
      function _totalBurned() internal view returns (uint256) {
          return _burnCounter;
      }
  
      /**
       * @dev See {IERC165-supportsInterface}.
       */
      function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
          // The interface IDs are constants representing the first 4 bytes of the XOR of
          // all function selectors in the interface. See: https://eips.ethereum.org/EIPS/eip-165
          // e.g. `bytes4(i.functionA.selector ^ i.functionB.selector ^ ...)`
          return
              interfaceId == 0x01ffc9a7 || // ERC165 interface ID for ERC165.
              interfaceId == 0x80ac58cd || // ERC165 interface ID for ERC721.
              interfaceId == 0x2a55205a || // ERC 2981 rotyalty
              interfaceId == 0x5b5e139f; // ERC165 interface ID for ERC721Metadata.
      }
  
      /**
       * @dev See {IERC721-balanceOf}.
       */
      function balanceOf(address owner) public view override returns (uint256) {
          if (owner == address(0)) revert BalanceQueryForZeroAddress();
          return _packedAddressData[owner] & BITMASK_ADDRESS_DATA_ENTRY;
      }
  
      /**
       * Returns the number of tokens minted by `owner`.
       */
      function _numberMinted(address owner) internal view returns (uint256) {
          return (_packedAddressData[owner] >> BITPOS_NUMBER_MINTED) & BITMASK_ADDRESS_DATA_ENTRY;
      }
  
      /**
       * Returns the number of tokens burned by or on behalf of `owner`.
       */
      function _numberBurned(address owner) internal view returns (uint256) {
          return (_packedAddressData[owner] >> BITPOS_NUMBER_BURNED) & BITMASK_ADDRESS_DATA_ENTRY;
      }
  
      /**
       * Returns the auxiliary data for `owner`. (e.g. number of whitelist mint slots used).
       */
      function _getAux(address owner) internal view returns (uint64) {
          return uint64(_packedAddressData[owner] >> BITPOS_AUX);
      }
  
      /**
       * Sets the auxiliary data for `owner`. (e.g. number of whitelist mint slots used).
       * If there are multiple variables, please pack them into a uint64.
       */
      function _setAux(address owner, uint64 aux) internal {
          uint256 packed = _packedAddressData[owner];
          uint256 auxCasted;
          // Cast `aux` with assembly to avoid redundant masking.
          assembly {
              auxCasted := aux
          }
          packed = (packed & BITMASK_AUX_COMPLEMENT) | (auxCasted << BITPOS_AUX);
          _packedAddressData[owner] = packed;
      }
  
      /**
       * Returns the packed ownership data of `tokenId`.
       */
      function _packedOwnershipOf(uint256 tokenId) private view returns (uint256) {
          uint256 curr = tokenId;
  
          unchecked {
              if (_startTokenId() <= curr)
                  if (curr < _currentIndex) {
                      uint256 packed = _packedOwnerships[curr];
                      // If not burned.
                      if (packed & BITMASK_BURNED == 0) {
                          // Invariant:
                          // There will always be an ownership that has an address and is not burned
                          // before an ownership that does not have an address and is not burned.
                          // Hence, curr will not underflow.
                          //
                          // We can directly compare the packed value.
                          // If the address is zero, packed is zero.
                          while (packed == 0) {
                              packed = _packedOwnerships[--curr];
                          }
                          return packed;
                      }
                  }
          }
          revert OwnerQueryForNonexistentToken();
      }
  
      /**
       * Returns the unpacked `TokenOwnership` struct from `packed`.
       */
      function _unpackedOwnership(uint256 packed) private pure returns (TokenOwnership memory ownership) {
          ownership.addr = address(uint160(packed));
          ownership.startTimestamp = uint64(packed >> BITPOS_START_TIMESTAMP);
          ownership.burned = packed & BITMASK_BURNED != 0;
          ownership.extraData = uint24(packed >> BITPOS_EXTRA_DATA);
      }
  
      /**
       * Returns the unpacked `TokenOwnership` struct at `index`.
       */
      function _ownershipAt(uint256 index) internal view returns (TokenOwnership memory) {
          return _unpackedOwnership(_packedOwnerships[index]);
      }
  
      /**
       * @dev Initializes the ownership slot minted at `index` for efficiency purposes.
       */
      function _initializeOwnershipAt(uint256 index) internal {
          if (_packedOwnerships[index] == 0) {
              _packedOwnerships[index] = _packedOwnershipOf(index);
          }
      }
  
      /**
       * Gas spent here starts off proportional to the maximum mint batch size.
       * It gradually moves to O(1) as tokens get transferred around in the collection over time.
       */
      function _ownershipOf(uint256 tokenId) internal view returns (TokenOwnership memory) {
          return _unpackedOwnership(_packedOwnershipOf(tokenId));
      }
  
      /**
       * @dev Packs ownership data into a single uint256.
       */
      function _packOwnershipData(address owner, uint256 flags) private view returns (uint256 result) {
          assembly {
              // Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.
              owner := and(owner, BITMASK_ADDRESS)
              // `owner | (block.timestamp << BITPOS_START_TIMESTAMP) | flags`.
              result := or(owner, or(shl(BITPOS_START_TIMESTAMP, timestamp()), flags))
          }
      }
  
      /**
       * @dev See {IERC721-ownerOf}.
       */
      function ownerOf(uint256 tokenId) public view override returns (address) {
          return address(uint160(_packedOwnershipOf(tokenId)));
      }
  
      /**
       * @dev See {IERC721Metadata-name}.
       */
      function name() public view virtual override returns (string memory) {
          return _name;
      }
  
      /**
       * @dev See {IERC721Metadata-symbol}.
       */
      function symbol() public view virtual override returns (string memory) {
          return _symbol;
      }
  
      /**
       * @dev See {IERC721Metadata-tokenURI}.
       */
      function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
          if (!_exists(tokenId)) revert URIQueryForNonexistentToken();
  
          string memory baseURI = _baseURI();
          return bytes(baseURI).length != 0 ? string(abi.encodePacked(baseURI, _toString(tokenId))) : '';
      }
  
      /**
       * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
       * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
       * by default, it can be overridden in child contracts.
       */
      function _baseURI() internal view virtual returns (string memory) {
          return '';
      }
  
      /**
       * @dev Returns the `nextInitialized` flag set if `quantity` equals 1.
       */
      function _nextInitializedFlag(uint256 quantity) private pure returns (uint256 result) {
          // For branchless setting of the `nextInitialized` flag.
          assembly {
              // `(quantity == 1) << BITPOS_NEXT_INITIALIZED`.
              result := shl(BITPOS_NEXT_INITIALIZED, eq(quantity, 1))
          }
      }
  
      /**
       * @dev See {IERC721-approve}.
       */
      function approve(address to, uint256 tokenId) public virtual override {
          address owner = ownerOf(tokenId);
          if (_msgSenderERC721A() != owner)
              if (!isApprovedForAll(owner, _msgSenderERC721A())) {
                  revert ApprovalCallerNotOwnerNorApproved();
              }
  
          _tokenApprovals[tokenId] = to;
          emit Approval(owner, to, tokenId);
      }
  
      /**
       * @dev See {IERC721-getApproved}.
       */
      function getApproved(uint256 tokenId) public view override returns (address) {
          if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();
  
          return _tokenApprovals[tokenId];
      }
  
      /**
       * @dev See {IERC721-setApprovalForAll}.
       */
      function setApprovalForAll(address operator, bool approved) public virtual override {
          if (operator == _msgSenderERC721A()) revert ApproveToCaller();
          _operatorApprovals[_msgSenderERC721A()][operator] = approved;
          emit ApprovalForAll(_msgSenderERC721A(), operator, approved);
      }
      
  
      /**
       * @dev See {IERC721-isApprovedForAll}.
       */
      function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
          return _operatorApprovals[owner][operator];
      }
  
      /**
       * @dev See {IERC721-safeTransferFrom}.
       */
      function safeTransferFrom(
          address from,
          address to,
          uint256 tokenId
      ) public virtual override {
          safeTransferFrom(from, to, tokenId, '');
      }
  
      /**
       * @dev See {IERC721-safeTransferFrom}.
       */
      function safeTransferFrom(
          address from,
          address to,
          uint256 tokenId,
          bytes memory _data
      ) public virtual override {
          transferFrom(from, to, tokenId);
          if (to.code.length != 0)
              if (!_checkContractOnERC721Received(from, to, tokenId, _data)) {
                  revert TransferToNonERC721ReceiverImplementer();
              }
      }
  
      /**
       * @dev Returns whether `tokenId` exists.
       *
       * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
       *
       * Tokens start existing when they are minted (`_mint`),
       */
      function _exists(uint256 tokenId) internal view returns (bool) {
          return
              _startTokenId() <= tokenId &&
              tokenId < _currentIndex && // If within bounds,
              _packedOwnerships[tokenId] & BITMASK_BURNED == 0; // and not burned.
      }
  
      /**
       * @dev Equivalent to `_safeMint(to, quantity, '')`.
       */
      function _safeMint(address to, uint256 quantity) internal {
          _safeMint(to, quantity, '');
      }
  
      /**
       * @dev Safely mints `quantity` tokens and transfers them to `to`.
       *
       * Requirements:
       *
       * - If `to` refers to a smart contract, it must implement
       *   {IERC721Receiver-onERC721Received}, which is called for each safe transfer.
       * - `quantity` must be greater than 0.
       *
       * See {_mint}.
       *
       * Emits a {Transfer} event for each mint.
       */
      function _safeMint(
          address to,
          uint256 quantity,
          bytes memory _data
      ) internal {
          _mint(to, quantity);
  
          unchecked {
              if (to.code.length != 0) {
                  uint256 end = _currentIndex;
                  uint256 index = end - quantity;
                  do {
                      if (!_checkContractOnERC721Received(address(0), to, index++, _data)) {
                          revert TransferToNonERC721ReceiverImplementer();
                      }
                  } while (index < end);
                  // Reentrancy protection.
                  if (_currentIndex != end) revert();
              }
          }
      }
  
      /**
       * @dev Mints `quantity` tokens and transfers them to `to`.
       *
       * Requirements:
       *
       * - `to` cannot be the zero address.
       * - `quantity` must be greater than 0.
       *
       * Emits a {Transfer} event for each mint.
       */
      function _mint(address to, uint256 quantity) internal {
          uint256 startTokenId = _currentIndex;
          if (to == address(0)) revert MintToZeroAddress();
          if (quantity == 0) revert MintZeroQuantity();
  
          _beforeTokenTransfers(address(0), to, startTokenId, quantity);
  
          // Overflows are incredibly unrealistic.
          // `balance` and `numberMinted` have a maximum limit of 2**64.
          // `tokenId` has a maximum limit of 2**256.
          unchecked {
              // Updates:
              // - `balance += quantity`.
              // - `numberMinted += quantity`.
              //
              // We can directly add to the `balance` and `numberMinted`.
              _packedAddressData[to] += quantity * ((1 << BITPOS_NUMBER_MINTED) | 1);
  
              // Updates:
              // - `address` to the owner.
              // - `startTimestamp` to the timestamp of minting.
              // - `burned` to `false`.
              // - `nextInitialized` to `quantity == 1`.
              _packedOwnerships[startTokenId] = _packOwnershipData(
                  to,
                  _nextInitializedFlag(quantity) | _nextExtraData(address(0), to, 0)
              );
  
              uint256 tokenId = startTokenId;
              uint256 end = startTokenId + quantity;
              do {
                  emit Transfer(address(0), to, tokenId++);
              } while (tokenId < end);
  
              _currentIndex = end;
          }
          _afterTokenTransfers(address(0), to, startTokenId, quantity);
      }
  
      /**
       * @dev Mints `quantity` tokens and transfers them to `to`.
       *
       * This function is intended for efficient minting only during contract creation.
       *
       * It emits only one {ConsecutiveTransfer} as defined in
       * [ERC2309](https://eips.ethereum.org/EIPS/eip-2309),
       * instead of a sequence of {Transfer} event(s).
       *
       * Calling this function outside of contract creation WILL make your contract
       * non-compliant with the ERC721 standard.
       * For full ERC721 compliance, substituting ERC721 {Transfer} event(s) with the ERC2309
       * {ConsecutiveTransfer} event is only permissible during contract creation.
       *
       * Requirements:
       *
       * - `to` cannot be the zero address.
       * - `quantity` must be greater than 0.
       *
       * Emits a {ConsecutiveTransfer} event.
       */
      function _mintERC2309(address to, uint256 quantity) internal {
          uint256 startTokenId = _currentIndex;
          if (to == address(0)) revert MintToZeroAddress();
          if (quantity == 0) revert MintZeroQuantity();
          if (quantity > MAX_MINT_ERC2309_QUANTITY_LIMIT) revert MintERC2309QuantityExceedsLimit();
  
          _beforeTokenTransfers(address(0), to, startTokenId, quantity);
  
          // Overflows are unrealistic due to the above check for `quantity` to be below the limit.
          unchecked {
              // Updates:
              // - `balance += quantity`.
              // - `numberMinted += quantity`.
              //
              // We can directly add to the `balance` and `numberMinted`.
              _packedAddressData[to] += quantity * ((1 << BITPOS_NUMBER_MINTED) | 1);
  
              // Updates:
              // - `address` to the owner.
              // - `startTimestamp` to the timestamp of minting.
              // - `burned` to `false`.
              // - `nextInitialized` to `quantity == 1`.
              _packedOwnerships[startTokenId] = _packOwnershipData(
                  to,
                  _nextInitializedFlag(quantity) | _nextExtraData(address(0), to, 0)
              );
  
              emit ConsecutiveTransfer(startTokenId, startTokenId + quantity - 1, address(0), to);
  
              _currentIndex = startTokenId + quantity;
          }
          _afterTokenTransfers(address(0), to, startTokenId, quantity);
      }
  
      /**
       * @dev Returns the storage slot and value for the approved address of `tokenId`.
       */
      function _getApprovedAddress(uint256 tokenId)
          private
          view
          returns (uint256 approvedAddressSlot, address approvedAddress)
      {
          mapping(uint256 => address) storage tokenApprovalsPtr = _tokenApprovals;
          // The following is equivalent to `approvedAddress = _tokenApprovals[tokenId]`.
          assembly {
              // Compute the slot.
              mstore(0x00, tokenId)
              mstore(0x20, tokenApprovalsPtr.slot)
              approvedAddressSlot := keccak256(0x00, 0x40)
              // Load the slot's value from storage.
              approvedAddress := sload(approvedAddressSlot)
          }
      }
  
      /**
       * @dev Returns whether the `approvedAddress` is equals to `from` or `msgSender`.
       */
      function _isOwnerOrApproved(
          address approvedAddress,
          address from,
          address msgSender
      ) private pure returns (bool result) {
          assembly {
              // Mask `from` to the lower 160 bits, in case the upper bits somehow aren't clean.
              from := and(from, BITMASK_ADDRESS)
              // Mask `msgSender` to the lower 160 bits, in case the upper bits somehow aren't clean.
              msgSender := and(msgSender, BITMASK_ADDRESS)
              // `msgSender == from || msgSender == approvedAddress`.
              result := or(eq(msgSender, from), eq(msgSender, approvedAddress))
          }
      }
  
      /**
       * @dev Transfers `tokenId` from `from` to `to`.
       *
       * Requirements:
       *
       * - `to` cannot be the zero address.
       * - `tokenId` token must be owned by `from`.
       *
       * Emits a {Transfer} event.
       */
      function transferFrom(
          address from,
          address to,
          uint256 tokenId
      ) public virtual override {
          uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);
  
          if (address(uint160(prevOwnershipPacked)) != from) revert TransferFromIncorrectOwner();
  
          (uint256 approvedAddressSlot, address approvedAddress) = _getApprovedAddress(tokenId);
  
          // The nested ifs save around 20+ gas over a compound boolean condition.
          if (!_isOwnerOrApproved(approvedAddress, from, _msgSenderERC721A()))
              if (!isApprovedForAll(from, _msgSenderERC721A())) revert TransferCallerNotOwnerNorApproved();
  
          if (to == address(0)) revert TransferToZeroAddress();
  
          _beforeTokenTransfers(from, to, tokenId, 1);
  
          // Clear approvals from the previous owner.
          assembly {
              if approvedAddress {
                  // This is equivalent to `delete _tokenApprovals[tokenId]`.
                  sstore(approvedAddressSlot, 0)
              }
          }
  
          // Underflow of the sender's balance is impossible because we check for
          // ownership above and the recipient's balance can't realistically overflow.
          // Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.
          unchecked {
              // We can directly increment and decrement the balances.
              --_packedAddressData[from]; // Updates: `balance -= 1`.
              ++_packedAddressData[to]; // Updates: `balance += 1`.
  
              // Updates:
              // - `address` to the next owner.
              // - `startTimestamp` to the timestamp of transfering.
              // - `burned` to `false`.
              // - `nextInitialized` to `true`.
              _packedOwnerships[tokenId] = _packOwnershipData(
                  to,
                  BITMASK_NEXT_INITIALIZED | _nextExtraData(from, to, prevOwnershipPacked)
              );
  
              // If the next slot may not have been initialized (i.e. `nextInitialized == false`) .
              if (prevOwnershipPacked & BITMASK_NEXT_INITIALIZED == 0) {
                  uint256 nextTokenId = tokenId + 1;
                  // If the next slot's address is zero and not burned (i.e. packed value is zero).
                  if (_packedOwnerships[nextTokenId] == 0) {
                      // If the next slot is within bounds.
                      if (nextTokenId != _currentIndex) {
                          // Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.
                          _packedOwnerships[nextTokenId] = prevOwnershipPacked;
                      }
                  }
              }
          }
  
          emit Transfer(from, to, tokenId);
          _afterTokenTransfers(from, to, tokenId, 1);
      }
  
      /**
       * @dev Equivalent to `_burn(tokenId, false)`.
       */
      function _burn(uint256 tokenId) internal virtual {
          _burn(tokenId, false);
      }
  
      /**
       * @dev Destroys `tokenId`.
       * The approval is cleared when the token is burned.
       *
       * Requirements:
       *
       * - `tokenId` must exist.
       *
       * Emits a {Transfer} event.
       */
      function _burn(uint256 tokenId, bool approvalCheck) internal virtual {
          uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);
  
          address from = address(uint160(prevOwnershipPacked));
  
          (uint256 approvedAddressSlot, address approvedAddress) = _getApprovedAddress(tokenId);
  
          if (approvalCheck) {
              // The nested ifs save around 20+ gas over a compound boolean condition.
              if (!_isOwnerOrApproved(approvedAddress, from, _msgSenderERC721A()))
                  if (!isApprovedForAll(from, _msgSenderERC721A())) revert TransferCallerNotOwnerNorApproved();
          }
  
          _beforeTokenTransfers(from, address(0), tokenId, 1);
  
          // Clear approvals from the previous owner.
          assembly {
              if approvedAddress {
                  // This is equivalent to `delete _tokenApprovals[tokenId]`.
                  sstore(approvedAddressSlot, 0)
              }
          }
  
          // Underflow of the sender's balance is impossible because we check for
          // ownership above and the recipient's balance can't realistically overflow.
          // Counter overflow is incredibly unrealistic as `tokenId` would have to be 2**256.
          unchecked {
              // Updates:
              // - `balance -= 1`.
              // - `numberBurned += 1`.
              //
              // We can directly decrement the balance, and increment the number burned.
              // This is equivalent to `packed -= 1; packed += 1 << BITPOS_NUMBER_BURNED;`.
              _packedAddressData[from] += (1 << BITPOS_NUMBER_BURNED) - 1;
  
              // Updates:
              // - `address` to the last owner.
              // - `startTimestamp` to the timestamp of burning.
              // - `burned` to `true`.
              // - `nextInitialized` to `true`.
              _packedOwnerships[tokenId] = _packOwnershipData(
                  from,
                  (BITMASK_BURNED | BITMASK_NEXT_INITIALIZED) | _nextExtraData(from, address(0), prevOwnershipPacked)
              );
  
              // If the next slot may not have been initialized (i.e. `nextInitialized == false`) .
              if (prevOwnershipPacked & BITMASK_NEXT_INITIALIZED == 0) {
                  uint256 nextTokenId = tokenId + 1;
                  // If the next slot's address is zero and not burned (i.e. packed value is zero).
                  if (_packedOwnerships[nextTokenId] == 0) {
                      // If the next slot is within bounds.
                      if (nextTokenId != _currentIndex) {
                          // Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.
                          _packedOwnerships[nextTokenId] = prevOwnershipPacked;
                      }
                  }
              }
          }
  
          emit Transfer(from, address(0), tokenId);
          _afterTokenTransfers(from, address(0), tokenId, 1);
  
          // Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.
          unchecked {
              _burnCounter++;
          }
      }
  
      /**
       * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target contract.
       *
       * @param from address representing the previous owner of the given token ID
       * @param to target address that will receive the tokens
       * @param tokenId uint256 ID of the token to be transferred
       * @param _data bytes optional data to send along with the call
       * @return bool whether the call correctly returned the expected magic value
       */
      function _checkContractOnERC721Received(
          address from,
          address to,
          uint256 tokenId,
          bytes memory _data
      ) private returns (bool) {
          try ERC721A__IERC721Receiver(to).onERC721Received(_msgSenderERC721A(), from, tokenId, _data) returns (
              bytes4 retval
          ) {
              return retval == ERC721A__IERC721Receiver(to).onERC721Received.selector;
          } catch (bytes memory reason) {
              if (reason.length == 0) {
                  revert TransferToNonERC721ReceiverImplementer();
              } else {
                  assembly {
                      revert(add(32, reason), mload(reason))
                  }
              }
          }
      }
  
      /**
       * @dev Directly sets the extra data for the ownership data `index`.
       */
      function _setExtraDataAt(uint256 index, uint24 extraData) internal {
          uint256 packed = _packedOwnerships[index];
          if (packed == 0) revert OwnershipNotInitializedForExtraData();
          uint256 extraDataCasted;
          // Cast `extraData` with assembly to avoid redundant masking.
          assembly {
              extraDataCasted := extraData
          }
          packed = (packed & BITMASK_EXTRA_DATA_COMPLEMENT) | (extraDataCasted << BITPOS_EXTRA_DATA);
          _packedOwnerships[index] = packed;
      }
  
      /**
       * @dev Returns the next extra data for the packed ownership data.
       * The returned result is shifted into position.
       */
      function _nextExtraData(
          address from,
          address to,
          uint256 prevOwnershipPacked
      ) private view returns (uint256) {
          uint24 extraData = uint24(prevOwnershipPacked >> BITPOS_EXTRA_DATA);
          return uint256(_extraData(from, to, extraData)) << BITPOS_EXTRA_DATA;
      }
  
      /**
       * @dev Called during each token transfer to set the 24bit `extraData` field.
       * Intended to be overridden by the cosumer contract.
       *
       * `previousExtraData` - the value of `extraData` before transfer.
       *
       * Calling conditions:
       *
       * - When `from` and `to` are both non-zero, `from`'s `tokenId` will be
       * transferred to `to`.
       * - When `from` is zero, `tokenId` will be minted for `to`.
       * - When `to` is zero, `tokenId` will be burned by `from`.
       * - `from` and `to` are never both zero.
       */
      function _extraData(
          address from,
          address to,
          uint24 previousExtraData
      ) internal view virtual returns (uint24) {}
  
      /**
       * @dev Hook that is called before a set of serially-ordered token ids are about to be transferred.
       * This includes minting.
       * And also called before burning one token.
       *
       * startTokenId - the first token id to be transferred
       * quantity - the amount to be transferred
       *
       * Calling conditions:
       *
       * - When `from` and `to` are both non-zero, `from`'s `tokenId` will be
       * transferred to `to`.
       * - When `from` is zero, `tokenId` will be minted for `to`.
       * - When `to` is zero, `tokenId` will be burned by `from`.
       * - `from` and `to` are never both zero.
       */
      function _beforeTokenTransfers(
          address from,
          address to,
          uint256 startTokenId,
          uint256 quantity
      ) internal virtual {}
  
      /**
       * @dev Hook that is called after a set of serially-ordered token ids have been transferred.
       * This includes minting.
       * And also called after one token has been burned.
       *
       * startTokenId - the first token id to be transferred
       * quantity - the amount to be transferred
       *
       * Calling conditions:
       *
       * - When `from` and `to` are both non-zero, `from`'s `tokenId` has been
       * transferred to `to`.
       * - When `from` is zero, `tokenId` has been minted for `to`.
       * - When `to` is zero, `tokenId` has been burned by `from`.
       * - `from` and `to` are never both zero.
       */
      function _afterTokenTransfers(
          address from,
          address to,
          uint256 startTokenId,
          uint256 quantity
      ) internal virtual {}
  
      /**
       * @dev Returns the message sender (defaults to `msg.sender`).
       *
       * If you are writing GSN compatible contracts, you need to override this function.
       */
      function _msgSenderERC721A() internal view virtual returns (address) {
          return msg.sender;
      }
  
      /**
       * @dev Converts a `uint256` to its ASCII `string` decimal representation.
       */
      function _toString(uint256 value) internal pure returns (string memory ptr) {
          assembly {
              // The maximum value of a uint256 contains 78 digits (1 byte per digit),
              // but we allocate 128 bytes to keep the free memory pointer 32-byte word aliged.
              // We will need 1 32-byte word to store the length,
              // and 3 32-byte words to store a maximum of 78 digits. Total: 32 + 3 * 32 = 128.
              ptr := add(mload(0x40), 128)
              // Update the free memory pointer to allocate.
              mstore(0x40, ptr)
  
              // Cache the end of the memory to calculate the length later.
              let end := ptr
  
              // We write the string from the rightmost digit to the leftmost digit.
              // The following is essentially a do-while loop that also handles the zero case.
              // Costs a bit more than early returning for the zero case,
              // but cheaper in terms of deployment and overall runtime costs.
              for {
                  // Initialize and perform the first pass without check.
                  let temp := value
                  // Move the pointer 1 byte leftwards to point to an empty character slot.
                  ptr := sub(ptr, 1)
                  // Write the character to the pointer. 48 is the ASCII index of '0'.
                  mstore8(ptr, add(48, mod(temp, 10)))
                  temp := div(temp, 10)
              } temp {
                  // Keep dividing `temp` until zero.
                  temp := div(temp, 10)
              } {
                  // Body of the for loop.
                  ptr := sub(ptr, 1)
                  mstore8(ptr, add(48, mod(temp, 10)))
              }
  
              let length := sub(end, ptr)
              // Move the pointer 32 bytes leftwards to make room for the length.
              ptr := sub(ptr, 32)
              // Store the length.
              mstore(ptr, length)
          }
      }
  }
  // File: @openzeppelin/contracts/utils/introspection/IERC165.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (utils/introspection/IERC165.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @dev Interface of the ERC165 standard, as defined in the
   * https://eips.ethereum.org/EIPS/eip-165[EIP].
   *
   * Implementers can declare support of contract interfaces, which can then be
   * queried by others ({ERC165Checker}).
   *
   * For an implementation, see {ERC165}.
   */
  interface IERC165 {
      /**
       * @dev Returns true if this contract implements the interface defined by
       * `interfaceId`. See the corresponding
       * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
       * to learn more about how these ids are created.
       *
       * This function call must use less than 30 000 gas.
       */
      function supportsInterface(bytes4 interfaceId) external view returns (bool);
  }
  
  // File: @openzeppelin/contracts/token/ERC721/IERC721.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC721/IERC721.sol)
  
  pragma solidity ^0.8.20;
  
  
  /**
   * @dev Required interface of an ERC721 compliant contract.
   */
  interface IERC721 is IERC165 {
      /**
       * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
       */
      event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
  
      /**
       * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
       */
      event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
  
      /**
       * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
       */
      event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
  
      /**
       * @dev Returns the number of tokens in ``owner``'s account.
       */
      function balanceOf(address owner) external view returns (uint256 balance);
  
      /**
       * @dev Returns the owner of the `tokenId` token.
       *
       * Requirements:
       *
       * - `tokenId` must exist.
       */
      function ownerOf(uint256 tokenId) external view returns (address owner);
  
      /**
       * @dev Safely transfers `tokenId` token from `from` to `to`.
       *
       * Requirements:
       *
       * - `from` cannot be the zero address.
       * - `to` cannot be the zero address.
       * - `tokenId` token must exist and be owned by `from`.
       * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
       * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon
       *   a safe transfer.
       *
       * Emits a {Transfer} event.
       */
      function safeTransferFrom(address from, address to, uint256 tokenId, bytes calldata data) external;
  
      /**
       * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
       * are aware of the ERC721 protocol to prevent tokens from being forever locked.
       *
       * Requirements:
       *
       * - `from` cannot be the zero address.
       * - `to` cannot be the zero address.
       * - `tokenId` token must exist and be owned by `from`.
       * - If the caller is not `from`, it must have been allowed to move this token by either {approve} or
       *   {setApprovalForAll}.
       * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon
       *   a safe transfer.
       *
       * Emits a {Transfer} event.
       */
      function safeTransferFrom(address from, address to, uint256 tokenId) external;
  
      /**
       * @dev Transfers `tokenId` token from `from` to `to`.
       *
       * WARNING: Note that the caller is responsible to confirm that the recipient is capable of receiving ERC721
       * or else they may be permanently lost. Usage of {safeTransferFrom} prevents loss, though the caller must
       * understand this adds an external call which potentially creates a reentrancy vulnerability.
       *
       * Requirements:
       *
       * - `from` cannot be the zero address.
       * - `to` cannot be the zero address.
       * - `tokenId` token must be owned by `from`.
       * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
       *
       * Emits a {Transfer} event.
       */
      function transferFrom(address from, address to, uint256 tokenId) external;
  
      /**
       * @dev Gives permission to `to` to transfer `tokenId` token to another account.
       * The approval is cleared when the token is transferred.
       *
       * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
       *
       * Requirements:
       *
       * - The caller must own the token or be an approved operator.
       * - `tokenId` must exist.
       *
       * Emits an {Approval} event.
       */
      function approve(address to, uint256 tokenId) external;
  
      /**
       * @dev Approve or remove `operator` as an operator for the caller.
       * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
       *
       * Requirements:
       *
       * - The `operator` cannot be the address zero.
       *
       * Emits an {ApprovalForAll} event.
       */
      function setApprovalForAll(address operator, bool approved) external;
  
      /**
       * @dev Returns the account approved for `tokenId` token.
       *
       * Requirements:
       *
       * - `tokenId` must exist.
       */
      function getApproved(uint256 tokenId) external view returns (address operator);
  
      /**
       * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
       *
       * See {setApprovalForAll}
       */
      function isApprovedForAll(address owner, address operator) external view returns (bool);
  }
  
  // File: @openzeppelin/contracts/utils/math/SignedMath.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (utils/math/SignedMath.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @dev Standard signed math utilities missing in the Solidity language.
   */
  library SignedMath {
      /**
       * @dev Returns the largest of two signed numbers.
       */
      function max(int256 a, int256 b) internal pure returns (int256) {
          return a > b ? a : b;
      }
  
      /**
       * @dev Returns the smallest of two signed numbers.
       */
      function min(int256 a, int256 b) internal pure returns (int256) {
          return a < b ? a : b;
      }
  
      /**
       * @dev Returns the average of two signed numbers without overflow.
       * The result is rounded towards zero.
       */
      function average(int256 a, int256 b) internal pure returns (int256) {
          // Formula from the book "Hacker's Delight"
          int256 x = (a & b) + ((a ^ b) >> 1);
          return x + (int256(uint256(x) >> 255) & (a ^ b));
      }
  
      /**
       * @dev Returns the absolute unsigned value of a signed value.
       */
      function abs(int256 n) internal pure returns (uint256) {
          unchecked {
              // must be unchecked in order to support `n = type(int256).min`
              return uint256(n >= 0 ? n : -n);
          }
      }
  }
  
  // File: @openzeppelin/contracts/utils/math/Math.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (utils/math/Math.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @dev Standard math utilities missing in the Solidity language.
   */
  library Math {
      /**
       * @dev Muldiv operation overflow.
       */
      error MathOverflowedMulDiv();
  
      enum Rounding {
          Floor, // Toward negative infinity
          Ceil, // Toward positive infinity
          Trunc, // Toward zero
          Expand // Away from zero
      }
  
      /**
       * @dev Returns the addition of two unsigned integers, with an overflow flag.
       */
      function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
          unchecked {
              uint256 c = a + b;
              if (c < a) return (false, 0);
              return (true, c);
          }
      }
  
      /**
       * @dev Returns the subtraction of two unsigned integers, with an overflow flag.
       */
      function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
          unchecked {
              if (b > a) return (false, 0);
              return (true, a - b);
          }
      }
  
      /**
       * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
       */
      function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
          unchecked {
              // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
              // benefit is lost if 'b' is also tested.
              // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
              if (a == 0) return (true, 0);
              uint256 c = a * b;
              if (c / a != b) return (false, 0);
              return (true, c);
          }
      }
  
      /**
       * @dev Returns the division of two unsigned integers, with a division by zero flag.
       */
      function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
          unchecked {
              if (b == 0) return (false, 0);
              return (true, a / b);
          }
      }
  
      /**
       * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
       */
      function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
          unchecked {
              if (b == 0) return (false, 0);
              return (true, a % b);
          }
      }
  
      /**
       * @dev Returns the largest of two numbers.
       */
      function max(uint256 a, uint256 b) internal pure returns (uint256) {
          return a > b ? a : b;
      }
  
      /**
       * @dev Returns the smallest of two numbers.
       */
      function min(uint256 a, uint256 b) internal pure returns (uint256) {
          return a < b ? a : b;
      }
  
      /**
       * @dev Returns the average of two numbers. The result is rounded towards
       * zero.
       */
      function average(uint256 a, uint256 b) internal pure returns (uint256) {
          // (a + b) / 2 can overflow.
          return (a & b) + (a ^ b) / 2;
      }
  
      /**
       * @dev Returns the ceiling of the division of two numbers.
       *
       * This differs from standard division with `/` in that it rounds towards infinity instead
       * of rounding towards zero.
       */
      function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
          if (b == 0) {
              // Guarantee the same behavior as in a regular Solidity division.
              return a / b;
          }
  
          // (a + b - 1) / b can overflow on addition, so we distribute.
          return a == 0 ? 0 : (a - 1) / b + 1;
      }
  
      /**
       * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or
       * denominator == 0.
       * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv) with further edits by
       * Uniswap Labs also under MIT license.
       */
      function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
          unchecked {
              // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
              // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
              // variables such that product = prod1 * 2^256 + prod0.
              uint256 prod0 = x * y; // Least significant 256 bits of the product
              uint256 prod1; // Most significant 256 bits of the product
              assembly {
                  let mm := mulmod(x, y, not(0))
                  prod1 := sub(sub(mm, prod0), lt(mm, prod0))
              }
  
              // Handle non-overflow cases, 256 by 256 division.
              if (prod1 == 0) {
                  // Solidity will revert if denominator == 0, unlike the div opcode on its own.
                  // The surrounding unchecked block does not change this fact.
                  // See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
                  return prod0 / denominator;
              }
  
              // Make sure the result is less than 2^256. Also prevents denominator == 0.
              if (denominator <= prod1) {
                  revert MathOverflowedMulDiv();
              }
  
              ///////////////////////////////////////////////
              // 512 by 256 division.
              ///////////////////////////////////////////////
  
              // Make division exact by subtracting the remainder from [prod1 prod0].
              uint256 remainder;
              assembly {
                  // Compute remainder using mulmod.
                  remainder := mulmod(x, y, denominator)
  
                  // Subtract 256 bit number from 512 bit number.
                  prod1 := sub(prod1, gt(remainder, prod0))
                  prod0 := sub(prod0, remainder)
              }
  
              // Factor powers of two out of denominator and compute largest power of two divisor of denominator.
              // Always >= 1. See https://cs.stackexchange.com/q/138556/92363.
  
              uint256 twos = denominator & (0 - denominator);
              assembly {
                  // Divide denominator by twos.
                  denominator := div(denominator, twos)
  
                  // Divide [prod1 prod0] by twos.
                  prod0 := div(prod0, twos)
  
                  // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                  twos := add(div(sub(0, twos), twos), 1)
              }
  
              // Shift in bits from prod1 into prod0.
              prod0 |= prod1 * twos;
  
              // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
              // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
              // four bits. That is, denominator * inv = 1 mod 2^4.
              uint256 inverse = (3 * denominator) ^ 2;
  
              // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also
              // works in modular arithmetic, doubling the correct bits in each step.
              inverse *= 2 - denominator * inverse; // inverse mod 2^8
              inverse *= 2 - denominator * inverse; // inverse mod 2^16
              inverse *= 2 - denominator * inverse; // inverse mod 2^32
              inverse *= 2 - denominator * inverse; // inverse mod 2^64
              inverse *= 2 - denominator * inverse; // inverse mod 2^128
              inverse *= 2 - denominator * inverse; // inverse mod 2^256
  
              // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
              // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
              // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
              // is no longer required.
              result = prod0 * inverse;
              return result;
          }
      }
  
      /**
       * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
       */
      function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
          uint256 result = mulDiv(x, y, denominator);
          if (unsignedRoundsUp(rounding) && mulmod(x, y, denominator) > 0) {
              result += 1;
          }
          return result;
      }
  
      /**
       * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded
       * towards zero.
       *
       * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
       */
      function sqrt(uint256 a) internal pure returns (uint256) {
          if (a == 0) {
              return 0;
          }
  
          // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
          //
          // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
          // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
          //
          // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
          // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
          // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
          //
          // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
          uint256 result = 1 << (log2(a) >> 1);
  
          // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
          // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
          // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
          // into the expected uint128 result.
          unchecked {
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              return min(result, a / result);
          }
      }
  
      /**
       * @notice Calculates sqrt(a), following the selected rounding direction.
       */
      function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
          unchecked {
              uint256 result = sqrt(a);
              return result + (unsignedRoundsUp(rounding) && result * result < a ? 1 : 0);
          }
      }
  
      /**
       * @dev Return the log in base 2 of a positive value rounded towards zero.
       * Returns 0 if given 0.
       */
      function log2(uint256 value) internal pure returns (uint256) {
          uint256 result = 0;
          unchecked {
              if (value >> 128 > 0) {
                  value >>= 128;
                  result += 128;
              }
              if (value >> 64 > 0) {
                  value >>= 64;
                  result += 64;
              }
              if (value >> 32 > 0) {
                  value >>= 32;
                  result += 32;
              }
              if (value >> 16 > 0) {
                  value >>= 16;
                  result += 16;
              }
              if (value >> 8 > 0) {
                  value >>= 8;
                  result += 8;
              }
              if (value >> 4 > 0) {
                  value >>= 4;
                  result += 4;
              }
              if (value >> 2 > 0) {
                  value >>= 2;
                  result += 2;
              }
              if (value >> 1 > 0) {
                  result += 1;
              }
          }
          return result;
      }
  
      /**
       * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
       * Returns 0 if given 0.
       */
      function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
          unchecked {
              uint256 result = log2(value);
              return result + (unsignedRoundsUp(rounding) && 1 << result < value ? 1 : 0);
          }
      }
  
      /**
       * @dev Return the log in base 10 of a positive value rounded towards zero.
       * Returns 0 if given 0.
       */
      function log10(uint256 value) internal pure returns (uint256) {
          uint256 result = 0;
          unchecked {
              if (value >= 10 ** 64) {
                  value /= 10 ** 64;
                  result += 64;
              }
              if (value >= 10 ** 32) {
                  value /= 10 ** 32;
                  result += 32;
              }
              if (value >= 10 ** 16) {
                  value /= 10 ** 16;
                  result += 16;
              }
              if (value >= 10 ** 8) {
                  value /= 10 ** 8;
                  result += 8;
              }
              if (value >= 10 ** 4) {
                  value /= 10 ** 4;
                  result += 4;
              }
              if (value >= 10 ** 2) {
                  value /= 10 ** 2;
                  result += 2;
              }
              if (value >= 10 ** 1) {
                  result += 1;
              }
          }
          return result;
      }
  
      /**
       * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
       * Returns 0 if given 0.
       */
      function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
          unchecked {
              uint256 result = log10(value);
              return result + (unsignedRoundsUp(rounding) && 10 ** result < value ? 1 : 0);
          }
      }
  
      /**
       * @dev Return the log in base 256 of a positive value rounded towards zero.
       * Returns 0 if given 0.
       *
       * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
       */
      function log256(uint256 value) internal pure returns (uint256) {
          uint256 result = 0;
          unchecked {
              if (value >> 128 > 0) {
                  value >>= 128;
                  result += 16;
              }
              if (value >> 64 > 0) {
                  value >>= 64;
                  result += 8;
              }
              if (value >> 32 > 0) {
                  value >>= 32;
                  result += 4;
              }
              if (value >> 16 > 0) {
                  value >>= 16;
                  result += 2;
              }
              if (value >> 8 > 0) {
                  result += 1;
              }
          }
          return result;
      }
  
      /**
       * @dev Return the log in base 256, following the selected rounding direction, of a positive value.
       * Returns 0 if given 0.
       */
      function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
          unchecked {
              uint256 result = log256(value);
              return result + (unsignedRoundsUp(rounding) && 1 << (result << 3) < value ? 1 : 0);
          }
      }
  
      /**
       * @dev Returns whether a provided rounding mode is considered rounding up for unsigned integers.
       */
      function unsignedRoundsUp(Rounding rounding) internal pure returns (bool) {
          return uint8(rounding) % 2 == 1;
      }
  }
  
  // File: @openzeppelin/contracts/utils/Strings.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (utils/Strings.sol)
  
  pragma solidity ^0.8.20;
  
  
  
  /**
   * @dev String operations.
   */
  library Strings {
      bytes16 private constant HEX_DIGITS = "0123456789abcdef";
      uint8 private constant ADDRESS_LENGTH = 20;
  
      /**
       * @dev The `value` string doesn't fit in the specified `length`.
       */
      error StringsInsufficientHexLength(uint256 value, uint256 length);
  
      /**
       * @dev Converts a `uint256` to its ASCII `string` decimal representation.
       */
      function toString(uint256 value) internal pure returns (string memory) {
          unchecked {
              uint256 length = Math.log10(value) + 1;
              string memory buffer = new string(length);
              uint256 ptr;
              /// @solidity memory-safe-assembly
              assembly {
                  ptr := add(buffer, add(32, length))
              }
              while (true) {
                  ptr--;
                  /// @solidity memory-safe-assembly
                  assembly {
                      mstore8(ptr, byte(mod(value, 10), HEX_DIGITS))
                  }
                  value /= 10;
                  if (value == 0) break;
              }
              return buffer;
          }
      }
  
      /**
       * @dev Converts a `int256` to its ASCII `string` decimal representation.
       */
      function toStringSigned(int256 value) internal pure returns (string memory) {
          return string.concat(value < 0 ? "-" : "", toString(SignedMath.abs(value)));
      }
  
      /**
       * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
       */
      function toHexString(uint256 value) internal pure returns (string memory) {
          unchecked {
              return toHexString(value, Math.log256(value) + 1);
          }
      }
  
      /**
       * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
       */
      function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
          uint256 localValue = value;
          bytes memory buffer = new bytes(2 * length + 2);
          buffer[0] = "0";
          buffer[1] = "x";
          for (uint256 i = 2 * length + 1; i > 1; --i) {
              buffer[i] = HEX_DIGITS[localValue & 0xf];
              localValue >>= 4;
          }
          if (localValue != 0) {
              revert StringsInsufficientHexLength(value, length);
          }
          return string(buffer);
      }
  
      /**
       * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal
       * representation.
       */
      function toHexString(address addr) internal pure returns (string memory) {
          return toHexString(uint256(uint160(addr)), ADDRESS_LENGTH);
      }
  
      /**
       * @dev Returns true if the two strings are equal.
       */
      function equal(string memory a, string memory b) internal pure returns (bool) {
          return bytes(a).length == bytes(b).length && keccak256(bytes(a)) == keccak256(bytes(b));
      }
  }
  
  // File: @openzeppelin/contracts/utils/Address.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (utils/Address.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @dev Collection of functions related to the address type
   */
  library Address {
      /**
       * @dev The ETH balance of the account is not enough to perform the operation.
       */
      error AddressInsufficientBalance(address account);
  
      /**
       * @dev There's no code at `target` (it is not a contract).
       */
      error AddressEmptyCode(address target);
  
      /**
       * @dev A call to an address target failed. The target may have reverted.
       */
      error FailedInnerCall();
  
      /**
       * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
       * `recipient`, forwarding all available gas and reverting on errors.
       *
       * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
       * of certain opcodes, possibly making contracts go over the 2300 gas limit
       * imposed by `transfer`, making them unable to receive funds via
       * `transfer`. {sendValue} removes this limitation.
       *
       * https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[Learn more].
       *
       * IMPORTANT: because control is transferred to `recipient`, care must be
       * taken to not create reentrancy vulnerabilities. Consider using
       * {ReentrancyGuard} or the
       * https://solidity.readthedocs.io/en/v0.8.20/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
       */
      function sendValue(address payable recipient, uint256 amount) internal {
          if (address(this).balance < amount) {
              revert AddressInsufficientBalance(address(this));
          }
  
          (bool success, ) = recipient.call{value: amount}("");
          if (!success) {
              revert FailedInnerCall();
          }
      }
  
      /**
       * @dev Performs a Solidity function call using a low level `call`. A
       * plain `call` is an unsafe replacement for a function call: use this
       * function instead.
       *
       * If `target` reverts with a revert reason or custom error, it is bubbled
       * up by this function (like regular Solidity function calls). However, if
       * the call reverted with no returned reason, this function reverts with a
       * {FailedInnerCall} error.
       *
       * Returns the raw returned data. To convert to the expected return value,
       * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
       *
       * Requirements:
       *
       * - `target` must be a contract.
       * - calling `target` with `data` must not revert.
       */
      function functionCall(address target, bytes memory data) internal returns (bytes memory) {
          return functionCallWithValue(target, data, 0);
      }
  
      /**
       * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
       * but also transferring `value` wei to `target`.
       *
       * Requirements:
       *
       * - the calling contract must have an ETH balance of at least `value`.
       * - the called Solidity function must be `payable`.
       */
      function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
          if (address(this).balance < value) {
              revert AddressInsufficientBalance(address(this));
          }
          (bool success, bytes memory returndata) = target.call{value: value}(data);
          return verifyCallResultFromTarget(target, success, returndata);
      }
  
      /**
       * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
       * but performing a static call.
       */
      function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
          (bool success, bytes memory returndata) = target.staticcall(data);
          return verifyCallResultFromTarget(target, success, returndata);
      }
  
      /**
       * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
       * but performing a delegate call.
       */
      function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
          (bool success, bytes memory returndata) = target.delegatecall(data);
          return verifyCallResultFromTarget(target, success, returndata);
      }
  
      /**
       * @dev Tool to verify that a low level call to smart-contract was successful, and reverts if the target
       * was not a contract or bubbling up the revert reason (falling back to {FailedInnerCall}) in case of an
       * unsuccessful call.
       */
      function verifyCallResultFromTarget(
          address target,
          bool success,
          bytes memory returndata
      ) internal view returns (bytes memory) {
          if (!success) {
              _revert(returndata);
          } else {
              // only check if target is a contract if the call was successful and the return data is empty
              // otherwise we already know that it was a contract
              if (returndata.length == 0 && target.code.length == 0) {
                  revert AddressEmptyCode(target);
              }
              return returndata;
          }
      }
  
      /**
       * @dev Tool to verify that a low level call was successful, and reverts if it wasn't, either by bubbling the
       * revert reason or with a default {FailedInnerCall} error.
       */
      function verifyCallResult(bool success, bytes memory returndata) internal pure returns (bytes memory) {
          if (!success) {
              _revert(returndata);
          } else {
              return returndata;
          }
      }
  
      /**
       * @dev Reverts with returndata if present. Otherwise reverts with {FailedInnerCall}.
       */
      function _revert(bytes memory returndata) private pure {
          // Look for revert reason and bubble it up if present
          if (returndata.length > 0) {
              // The easiest way to bubble the revert reason is using memory via assembly
              /// @solidity memory-safe-assembly
              assembly {
                  let returndata_size := mload(returndata)
                  revert(add(32, returndata), returndata_size)
              }
          } else {
              revert FailedInnerCall();
          }
      }
  }
  
  // File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Permit.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/IERC20Permit.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
   * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
   *
   * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
   * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
   * need to send a transaction, and thus is not required to hold Ether at all.
   *
   * ==== Security Considerations
   *
   * There are two important considerations concerning the use of `permit`. The first is that a valid permit signature
   * expresses an allowance, and it should not be assumed to convey additional meaning. In particular, it should not be
   * considered as an intention to spend the allowance in any specific way. The second is that because permits have
   * built-in replay protection and can be submitted by anyone, they can be frontrun. A protocol that uses permits should
   * take this into consideration and allow a `permit` call to fail. Combining these two aspects, a pattern that may be
   * generally recommended is:
   *
   * ```solidity
   * function doThingWithPermit(..., uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public {
   *     try token.permit(msg.sender, address(this), value, deadline, v, r, s) {} catch {}
   *     doThing(..., value);
   * }
   *
   * function doThing(..., uint256 value) public {
   *     token.safeTransferFrom(msg.sender, address(this), value);
   *     ...
   * }
   * ```
   *
   * Observe that: 1) `msg.sender` is used as the owner, leaving no ambiguity as to the signer intent, and 2) the use of
   * `try/catch` allows the permit to fail and makes the code tolerant to frontrunning. (See also
   * {SafeERC20-safeTransferFrom}).
   *
   * Additionally, note that smart contract wallets (such as Argent or Safe) are not able to produce permit signatures, so
   * contracts should have entry points that don't rely on permit.
   */
  interface IERC20Permit {
      /**
       * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
       * given ``owner``'s signed approval.
       *
       * IMPORTANT: The same issues {IERC20-approve} has related to transaction
       * ordering also apply here.
       *
       * Emits an {Approval} event.
       *
       * Requirements:
       *
       * - `spender` cannot be the zero address.
       * - `deadline` must be a timestamp in the future.
       * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
       * over the EIP712-formatted function arguments.
       * - the signature must use ``owner``'s current nonce (see {nonces}).
       *
       * For more information on the signature format, see the
       * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
       * section].
       *
       * CAUTION: See Security Considerations above.
       */
      function permit(
          address owner,
          address spender,
          uint256 value,
          uint256 deadline,
          uint8 v,
          bytes32 r,
          bytes32 s
      ) external;
  
      /**
       * @dev Returns the current nonce for `owner`. This value must be
       * included whenever a signature is generated for {permit}.
       *
       * Every successful call to {permit} increases ``owner``'s nonce by one. This
       * prevents a signature from being used multiple times.
       */
      function nonces(address owner) external view returns (uint256);
  
      /**
       * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
       */
      // solhint-disable-next-line func-name-mixedcase
      function DOMAIN_SEPARATOR() external view returns (bytes32);
  }
  
  // File: @openzeppelin/contracts/token/ERC20/IERC20.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/IERC20.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @dev Interface of the ERC20 standard as defined in the EIP.
   */
  interface IERC20 {
      /**
       * @dev Emitted when `value` tokens are moved from one account (`from`) to
       * another (`to`).
       *
       * Note that `value` may be zero.
       */
      event Transfer(address indexed from, address indexed to, uint256 value);
  
      /**
       * @dev Emitted when the allowance of a `spender` for an `owner` is set by
       * a call to {approve}. `value` is the new allowance.
       */
      event Approval(address indexed owner, address indexed spender, uint256 value);
  
      /**
       * @dev Returns the value of tokens in existence.
       */
      function totalSupply() external view returns (uint256);
  
      /**
       * @dev Returns the value of tokens owned by `account`.
       */
      function balanceOf(address account) external view returns (uint256);
  
      /**
       * @dev Moves a `value` amount of tokens from the caller's account to `to`.
       *
       * Returns a boolean value indicating whether the operation succeeded.
       *
       * Emits a {Transfer} event.
       */
      function transfer(address to, uint256 value) external returns (bool);
  
      /**
       * @dev Returns the remaining number of tokens that `spender` will be
       * allowed to spend on behalf of `owner` through {transferFrom}. This is
       * zero by default.
       *
       * This value changes when {approve} or {transferFrom} are called.
       */
      function allowance(address owner, address spender) external view returns (uint256);
  
      /**
       * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
       * caller's tokens.
       *
       * Returns a boolean value indicating whether the operation succeeded.
       *
       * IMPORTANT: Beware that changing an allowance with this method brings the risk
       * that someone may use both the old and the new allowance by unfortunate
       * transaction ordering. One possible solution to mitigate this race
       * condition is to first reduce the spender's allowance to 0 and set the
       * desired value afterwards:
       * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
       *
       * Emits an {Approval} event.
       */
      function approve(address spender, uint256 value) external returns (bool);
  
      /**
       * @dev Moves a `value` amount of tokens from `from` to `to` using the
       * allowance mechanism. `value` is then deducted from the caller's
       * allowance.
       *
       * Returns a boolean value indicating whether the operation succeeded.
       *
       * Emits a {Transfer} event.
       */
      function transferFrom(address from, address to, uint256 value) external returns (bool);
  }
  
  // File: @openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/utils/SafeERC20.sol)
  
  pragma solidity ^0.8.20;
  
  
  
  
  /**
   * @title SafeERC20
   * @dev Wrappers around ERC20 operations that throw on failure (when the token
   * contract returns false). Tokens that return no value (and instead revert or
   * throw on failure) are also supported, non-reverting calls are assumed to be
   * successful.
   * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
   * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
   */
  library SafeERC20 {
      using Address for address;
  
      /**
       * @dev An operation with an ERC20 token failed.
       */
      error SafeERC20FailedOperation(address token);
  
      /**
       * @dev Indicates a failed `decreaseAllowance` request.
       */
      error SafeERC20FailedDecreaseAllowance(address spender, uint256 currentAllowance, uint256 requestedDecrease);
  
      /**
       * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
       * non-reverting calls are assumed to be successful.
       */
      function safeTransfer(IERC20 token, address to, uint256 value) internal {
          _callOptionalReturn(token, abi.encodeCall(token.transfer, (to, value)));
      }
  
      /**
       * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
       * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
       */
      function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
          _callOptionalReturn(token, abi.encodeCall(token.transferFrom, (from, to, value)));
      }
  
      /**
       * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
       * non-reverting calls are assumed to be successful.
       */
      function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
          uint256 oldAllowance = token.allowance(address(this), spender);
          forceApprove(token, spender, oldAllowance + value);
      }
  
      /**
       * @dev Decrease the calling contract's allowance toward `spender` by `requestedDecrease`. If `token` returns no
       * value, non-reverting calls are assumed to be successful.
       */
      function safeDecreaseAllowance(IERC20 token, address spender, uint256 requestedDecrease) internal {
          unchecked {
              uint256 currentAllowance = token.allowance(address(this), spender);
              if (currentAllowance < requestedDecrease) {
                  revert SafeERC20FailedDecreaseAllowance(spender, currentAllowance, requestedDecrease);
              }
              forceApprove(token, spender, currentAllowance - requestedDecrease);
          }
      }
  
      /**
       * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
       * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
       * to be set to zero before setting it to a non-zero value, such as USDT.
       */
      function forceApprove(IERC20 token, address spender, uint256 value) internal {
          bytes memory approvalCall = abi.encodeCall(token.approve, (spender, value));
  
          if (!_callOptionalReturnBool(token, approvalCall)) {
              _callOptionalReturn(token, abi.encodeCall(token.approve, (spender, 0)));
              _callOptionalReturn(token, approvalCall);
          }
      }
  
      /**
       * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
       * on the return value: the return value is optional (but if data is returned, it must not be false).
       * @param token The token targeted by the call.
       * @param data The call data (encoded using abi.encode or one of its variants).
       */
      function _callOptionalReturn(IERC20 token, bytes memory data) private {
          // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
          // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
          // the target address contains contract code and also asserts for success in the low-level call.
  
          bytes memory returndata = address(token).functionCall(data);
          if (returndata.length != 0 && !abi.decode(returndata, (bool))) {
              revert SafeERC20FailedOperation(address(token));
          }
      }
  
      /**
       * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
       * on the return value: the return value is optional (but if data is returned, it must not be false).
       * @param token The token targeted by the call.
       * @param data The call data (encoded using abi.encode or one of its variants).
       *
       * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
       */
      function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
          // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
          // we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
          // and not revert is the subcall reverts.
  
          (bool success, bytes memory returndata) = address(token).call(data);
          return success && (returndata.length == 0 || abi.decode(returndata, (bool))) && address(token).code.length > 0;
      }
  }
  
  // File: @openzeppelin/contracts/utils/cryptography/MerkleProof.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (utils/cryptography/MerkleProof.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @dev These functions deal with verification of Merkle Tree proofs.
   *
   * The tree and the proofs can be generated using our
   * https://github.com/OpenZeppelin/merkle-tree[JavaScript library].
   * You will find a quickstart guide in the readme.
   *
   * WARNING: You should avoid using leaf values that are 64 bytes long prior to
   * hashing, or use a hash function other than keccak256 for hashing leaves.
   * This is because the concatenation of a sorted pair of internal nodes in
   * the Merkle tree could be reinterpreted as a leaf value.
   * OpenZeppelin's JavaScript library generates Merkle trees that are safe
   * against this attack out of the box.
   */
  library MerkleProof {
      /**
       *@dev The multiproof provided is not valid.
       */
      error MerkleProofInvalidMultiproof();
  
      /**
       * @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree
       * defined by `root`. For this, a `proof` must be provided, containing
       * sibling hashes on the branch from the leaf to the root of the tree. Each
       * pair of leaves and each pair of pre-images are assumed to be sorted.
       */
      function verify(bytes32[] memory proof, bytes32 root, bytes32 leaf) internal pure returns (bool) {
          return processProof(proof, leaf) == root;
      }
  
      /**
       * @dev Calldata version of {verify}
       */
      function verifyCalldata(bytes32[] calldata proof, bytes32 root, bytes32 leaf) internal pure returns (bool) {
          return processProofCalldata(proof, leaf) == root;
      }
  
      /**
       * @dev Returns the rebuilt hash obtained by traversing a Merkle tree up
       * from `leaf` using `proof`. A `proof` is valid if and only if the rebuilt
       * hash matches the root of the tree. When processing the proof, the pairs
       * of leafs & pre-images are assumed to be sorted.
       */
      function processProof(bytes32[] memory proof, bytes32 leaf) internal pure returns (bytes32) {
          bytes32 computedHash = leaf;
          for (uint256 i = 0; i < proof.length; i++) {
              computedHash = _hashPair(computedHash, proof[i]);
          }
          return computedHash;
      }
  
      /**
       * @dev Calldata version of {processProof}
       */
      function processProofCalldata(bytes32[] calldata proof, bytes32 leaf) internal pure returns (bytes32) {
          bytes32 computedHash = leaf;
          for (uint256 i = 0; i < proof.length; i++) {
              computedHash = _hashPair(computedHash, proof[i]);
          }
          return computedHash;
      }
  
      /**
       * @dev Returns true if the `leaves` can be simultaneously proven to be a part of a Merkle tree defined by
       * `root`, according to `proof` and `proofFlags` as described in {processMultiProof}.
       *
       * CAUTION: Not all Merkle trees admit multiproofs. See {processMultiProof} for details.
       */
      function multiProofVerify(
          bytes32[] memory proof,
          bool[] memory proofFlags,
          bytes32 root,
          bytes32[] memory leaves
      ) internal pure returns (bool) {
          return processMultiProof(proof, proofFlags, leaves) == root;
      }
  
      /**
       * @dev Calldata version of {multiProofVerify}
       *
       * CAUTION: Not all Merkle trees admit multiproofs. See {processMultiProof} for details.
       */
      function multiProofVerifyCalldata(
          bytes32[] calldata proof,
          bool[] calldata proofFlags,
          bytes32 root,
          bytes32[] memory leaves
      ) internal pure returns (bool) {
          return processMultiProofCalldata(proof, proofFlags, leaves) == root;
      }
  
      /**
       * @dev Returns the root of a tree reconstructed from `leaves` and sibling nodes in `proof`. The reconstruction
       * proceeds by incrementally reconstructing all inner nodes by combining a leaf/inner node with either another
       * leaf/inner node or a proof sibling node, depending on whether each `proofFlags` item is true or false
       * respectively.
       *
       * CAUTION: Not all Merkle trees admit multiproofs. To use multiproofs, it is sufficient to ensure that: 1) the tree
       * is complete (but not necessarily perfect), 2) the leaves to be proven are in the opposite order they are in the
       * tree (i.e., as seen from right to left starting at the deepest layer and continuing at the next layer).
       */
      function processMultiProof(
          bytes32[] memory proof,
          bool[] memory proofFlags,
          bytes32[] memory leaves
      ) internal pure returns (bytes32 merkleRoot) {
          // This function rebuilds the root hash by traversing the tree up from the leaves. The root is rebuilt by
          // consuming and producing values on a queue. The queue starts with the `leaves` array, then goes onto the
          // `hashes` array. At the end of the process, the last hash in the `hashes` array should contain the root of
          // the Merkle tree.
          uint256 leavesLen = leaves.length;
          uint256 proofLen = proof.length;
          uint256 totalHashes = proofFlags.length;
  
          // Check proof validity.
          if (leavesLen + proofLen != totalHashes + 1) {
              revert MerkleProofInvalidMultiproof();
          }
  
          // The xxxPos values are "pointers" to the next value to consume in each array. All accesses are done using
          // `xxx[xxxPos++]`, which return the current value and increment the pointer, thus mimicking a queue's "pop".
          bytes32[] memory hashes = new bytes32[](totalHashes);
          uint256 leafPos = 0;
          uint256 hashPos = 0;
          uint256 proofPos = 0;
          // At each step, we compute the next hash using two values:
          // - a value from the "main queue". If not all leaves have been consumed, we get the next leaf, otherwise we
          //   get the next hash.
          // - depending on the flag, either another value from the "main queue" (merging branches) or an element from the
          //   `proof` array.
          for (uint256 i = 0; i < totalHashes; i++) {
              bytes32 a = leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++];
              bytes32 b = proofFlags[i]
                  ? (leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++])
                  : proof[proofPos++];
              hashes[i] = _hashPair(a, b);
          }
  
          if (totalHashes > 0) {
              if (proofPos != proofLen) {
                  revert MerkleProofInvalidMultiproof();
              }
              unchecked {
                  return hashes[totalHashes - 1];
              }
          } else if (leavesLen > 0) {
              return leaves[0];
          } else {
              return proof[0];
          }
      }
  
      /**
       * @dev Calldata version of {processMultiProof}.
       *
       * CAUTION: Not all Merkle trees admit multiproofs. See {processMultiProof} for details.
       */
      function processMultiProofCalldata(
          bytes32[] calldata proof,
          bool[] calldata proofFlags,
          bytes32[] memory leaves
      ) internal pure returns (bytes32 merkleRoot) {
          // This function rebuilds the root hash by traversing the tree up from the leaves. The root is rebuilt by
          // consuming and producing values on a queue. The queue starts with the `leaves` array, then goes onto the
          // `hashes` array. At the end of the process, the last hash in the `hashes` array should contain the root of
          // the Merkle tree.
          uint256 leavesLen = leaves.length;
          uint256 proofLen = proof.length;
          uint256 totalHashes = proofFlags.length;
  
          // Check proof validity.
          if (leavesLen + proofLen != totalHashes + 1) {
              revert MerkleProofInvalidMultiproof();
          }
  
          // The xxxPos values are "pointers" to the next value to consume in each array. All accesses are done using
          // `xxx[xxxPos++]`, which return the current value and increment the pointer, thus mimicking a queue's "pop".
          bytes32[] memory hashes = new bytes32[](totalHashes);
          uint256 leafPos = 0;
          uint256 hashPos = 0;
          uint256 proofPos = 0;
          // At each step, we compute the next hash using two values:
          // - a value from the "main queue". If not all leaves have been consumed, we get the next leaf, otherwise we
          //   get the next hash.
          // - depending on the flag, either another value from the "main queue" (merging branches) or an element from the
          //   `proof` array.
          for (uint256 i = 0; i < totalHashes; i++) {
              bytes32 a = leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++];
              bytes32 b = proofFlags[i]
                  ? (leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++])
                  : proof[proofPos++];
              hashes[i] = _hashPair(a, b);
          }
  
          if (totalHashes > 0) {
              if (proofPos != proofLen) {
                  revert MerkleProofInvalidMultiproof();
              }
              unchecked {
                  return hashes[totalHashes - 1];
              }
          } else if (leavesLen > 0) {
              return leaves[0];
          } else {
              return proof[0];
          }
      }
  
      /**
       * @dev Sorts the pair (a, b) and hashes the result.
       */
      function _hashPair(bytes32 a, bytes32 b) private pure returns (bytes32) {
          return a < b ? _efficientHash(a, b) : _efficientHash(b, a);
      }
  
      /**
       * @dev Implementation of keccak256(abi.encode(a, b)) that doesn't allocate or expand memory.
       */
      function _efficientHash(bytes32 a, bytes32 b) private pure returns (bytes32 value) {
          /// @solidity memory-safe-assembly
          assembly {
              mstore(0x00, a)
              mstore(0x20, b)
              value := keccak256(0x00, 0x40)
          }
      }
  }
  
  // File: @openzeppelin/contracts/utils/Context.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @dev Provides information about the current execution context, including the
   * sender of the transaction and its data. While these are generally available
   * via msg.sender and msg.data, they should not be accessed in such a direct
   * manner, since when dealing with meta-transactions the account sending and
   * paying for execution may not be the actual sender (as far as an application
   * is concerned).
   *
   * This contract is only required for intermediate, library-like contracts.
   */
  abstract contract Context {
      function _msgSender() internal view virtual returns (address) {
          return msg.sender;
      }
  
      function _msgData() internal view virtual returns (bytes calldata) {
          return msg.data;
      }
  
      function _contextSuffixLength() internal view virtual returns (uint256) {
          return 0;
      }
  }
  
  // File: @openzeppelin/contracts/finance/PaymentSplitter.sol
  
  
  // OpenZeppelin Contracts (last updated v4.8.0) (finance/PaymentSplitter.sol)
  
  pragma solidity ^0.8.0;
  
  
  
  
  /**
   * @title PaymentSplitter
   * @dev This contract allows to split Ether payments among a group of accounts. The sender does not need to be aware
   * that the Ether will be split in this way, since it is handled transparently by the contract.
   *
   * The split can be in equal parts or in any other arbitrary proportion. The way this is specified is by assigning each
   * account to a number of shares. Of all the Ether that this contract receives, each account will then be able to claim
   * an amount proportional to the percentage of total shares they were assigned. The distribution of shares is set at the
   * time of contract deployment and can't be updated thereafter.
   *
   * `PaymentSplitter` follows a _pull payment_ model. This means that payments are not automatically forwarded to the
   * accounts but kept in this contract, and the actual transfer is triggered as a separate step by calling the {release}
   * function.
   *
   * NOTE: This contract assumes that ERC20 tokens will behave similarly to native tokens (Ether). Rebasing tokens, and
   * tokens that apply fees during transfers, are likely to not be supported as expected. If in doubt, we encourage you
   * to run tests before sending real value to this contract.
   */
  contract PaymentSplitter is Context {
      event PayeeAdded(address account, uint256 shares);
      event PaymentReleased(address to, uint256 amount);
      event ERC20PaymentReleased(IERC20 indexed token, address to, uint256 amount);
      event PaymentReceived(address from, uint256 amount);
  
      uint256 private _totalShares;
      uint256 private _totalReleased;
  
      mapping(address => uint256) private _shares;
      mapping(address => uint256) private _released;
      address[] private _payees;
  
      mapping(IERC20 => uint256) private _erc20TotalReleased;
      mapping(IERC20 => mapping(address => uint256)) private _erc20Released;
  
      /**
       * @dev Creates an instance of `PaymentSplitter` where each account in `payees` is assigned the number of shares at
       * the matching position in the `shares` array.
       *
       * All addresses in `payees` must be non-zero. Both arrays must have the same non-zero length, and there must be no
       * duplicates in `payees`.
       */
      constructor(address[] memory payees, uint256[] memory shares_) payable {
          require(payees.length == shares_.length, "PaymentSplitter: payees and shares length mismatch");
          require(payees.length > 0, "PaymentSplitter: no payees");
  
          for (uint256 i = 0; i < payees.length; i++) {
              _addPayee(payees[i], shares_[i]);
          }
      }
  
      /**
       * @dev The Ether received will be logged with {PaymentReceived} events. Note that these events are not fully
       * reliable: it's possible for a contract to receive Ether without triggering this function. This only affects the
       * reliability of the events, and not the actual splitting of Ether.
       *
       * To learn more about this see the Solidity documentation for
       * https://solidity.readthedocs.io/en/latest/contracts.html#fallback-function[fallback
       * functions].
       */
      receive() external payable virtual {
          emit PaymentReceived(_msgSender(), msg.value);
      }
  
      /**
       * @dev Getter for the total shares held by payees.
       */
      function totalShares() public view returns (uint256) {
          return _totalShares;
      }
  
      /**
       * @dev Getter for the total amount of Ether already released.
       */
      function totalReleased() public view returns (uint256) {
          return _totalReleased;
      }
  
      /**
       * @dev Getter for the total amount of `token` already released. `token` should be the address of an IERC20
       * contract.
       */
      function totalReleased(IERC20 token) public view returns (uint256) {
          return _erc20TotalReleased[token];
      }
  
      /**
       * @dev Getter for the amount of shares held by an account.
       */
      function shares(address account) public view returns (uint256) {
          return _shares[account];
      }
  
      /**
       * @dev Getter for the amount of Ether already released to a payee.
       */
      function released(address account) public view returns (uint256) {
          return _released[account];
      }
  
      /**
       * @dev Getter for the amount of `token` tokens already released to a payee. `token` should be the address of an
       * IERC20 contract.
       */
      function released(IERC20 token, address account) public view returns (uint256) {
          return _erc20Released[token][account];
      }
  
      /**
       * @dev Getter for the address of the payee number `index`.
       */
      function payee(uint256 index) public view returns (address) {
          return _payees[index];
      }
  
      /**
       * @dev Getter for the amount of payee's releasable Ether.
       */
      function releasable(address account) public view returns (uint256) {
          uint256 totalReceived = address(this).balance + totalReleased();
          return _pendingPayment(account, totalReceived, released(account));
      }
  
      /**
       * @dev Getter for the amount of payee's releasable `token` tokens. `token` should be the address of an
       * IERC20 contract.
       */
      function releasable(IERC20 token, address account) public view returns (uint256) {
          uint256 totalReceived = token.balanceOf(address(this)) + totalReleased(token);
          return _pendingPayment(account, totalReceived, released(token, account));
      }
  
      /**
       * @dev Triggers a transfer to `account` of the amount of Ether they are owed, according to their percentage of the
       * total shares and their previous withdrawals.
       */
      function release(address payable account) public virtual {
          require(_shares[account] > 0, "PaymentSplitter: account has no shares");
  
          uint256 payment = releasable(account);
  
          require(payment != 0, "PaymentSplitter: account is not due payment");
  
          // _totalReleased is the sum of all values in _released.
          // If "_totalReleased += payment" does not overflow, then "_released[account] += payment" cannot overflow.
          _totalReleased += payment;
          unchecked {
              _released[account] += payment;
          }
  
          Address.sendValue(account, payment);
          emit PaymentReleased(account, payment);
      }
  
      /**
       * @dev Triggers a transfer to `account` of the amount of `token` tokens they are owed, according to their
       * percentage of the total shares and their previous withdrawals. `token` must be the address of an IERC20
       * contract.
       */
      function release(IERC20 token, address account) public virtual {
          require(_shares[account] > 0, "PaymentSplitter: account has no shares");
  
          uint256 payment = releasable(token, account);
  
          require(payment != 0, "PaymentSplitter: account is not due payment");
  
          // _erc20TotalReleased[token] is the sum of all values in _erc20Released[token].
          // If "_erc20TotalReleased[token] += payment" does not overflow, then "_erc20Released[token][account] += payment"
          // cannot overflow.
          _erc20TotalReleased[token] += payment;
          unchecked {
              _erc20Released[token][account] += payment;
          }
  
          SafeERC20.safeTransfer(token, account, payment);
          emit ERC20PaymentReleased(token, account, payment);
      }
  
      /**
       * @dev internal logic for computing the pending payment of an `account` given the token historical balances and
       * already released amounts.
       */
      function _pendingPayment(
          address account,
          uint256 totalReceived,
          uint256 alreadyReleased
      ) private view returns (uint256) {
          return (totalReceived * _shares[account]) / _totalShares - alreadyReleased;
      }
  
      /**
       * @dev Add a new payee to the contract.
       * @param account The address of the payee to add.
       * @param shares_ The number of shares owned by the payee.
       */
      function _addPayee(address account, uint256 shares_) private {
          require(account != address(0), "PaymentSplitter: account is the zero address");
          require(shares_ > 0, "PaymentSplitter: shares are 0");
          require(_shares[account] == 0, "PaymentSplitter: account already has shares");
  
          _payees.push(account);
          _shares[account] = shares_;
          _totalShares = _totalShares + shares_;
          emit PayeeAdded(account, shares_);
      }
  }
  
  // File: @openzeppelin/contracts/access/Ownable.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)
  
  pragma solidity ^0.8.20;
  
  
  /**
   * @dev Contract module which provides a basic access control mechanism, where
   * there is an account (an owner) that can be granted exclusive access to
   * specific functions.
   *
   * The initial owner is set to the address provided by the deployer. This can
   * later be changed with {transferOwnership}.
   *
   * This module is used through inheritance. It will make available the modifier
   * `onlyOwner`, which can be applied to your functions to restrict their use to
   * the owner.
   */
  abstract contract Ownable is Context {
      address private _owner;
  
      /**
       * @dev The caller account is not authorized to perform an operation.
       */
      error OwnableUnauthorizedAccount(address account);
  
      /**
       * @dev The owner is not a valid owner account. (eg. `address(0)`)
       */
      error OwnableInvalidOwner(address owner);
  
      event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
  
      /**
       * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
       */
      constructor(address initialOwner) {
          if (initialOwner == address(0)) {
              revert OwnableInvalidOwner(address(0));
          }
          _transferOwnership(initialOwner);
      }
  
      /**
       * @dev Throws if called by any account other than the owner.
       */
      modifier onlyOwner() {
          _checkOwner();
          _;
      }
  
      /**
       * @dev Returns the address of the current owner.
       */
      function owner() public view virtual returns (address) {
          return _owner;
      }
  
      /**
       * @dev Throws if the sender is not the owner.
       */
      function _checkOwner() internal view virtual {
          if (owner() != _msgSender()) {
              revert OwnableUnauthorizedAccount(_msgSender());
          }
      }
  
      /**
       * @dev Leaves the contract without owner. It will not be possible to call
       * `onlyOwner` functions. Can only be called by the current owner.
       *
       * NOTE: Renouncing ownership will leave the contract without an owner,
       * thereby disabling any functionality that is only available to the owner.
       */
      function renounceOwnership() public virtual onlyOwner {
          _transferOwnership(address(0));
      }
  
      /**
       * @dev Transfers ownership of the contract to a new account (`newOwner`).
       * Can only be called by the current owner.
       */
      function transferOwnership(address newOwner) public virtual onlyOwner {
          if (newOwner == address(0)) {
              revert OwnableInvalidOwner(address(0));
          }
          _transferOwnership(newOwner);
      }
  
      /**
       * @dev Transfers ownership of the contract to a new account (`newOwner`).
       * Internal function without access restriction.
       */
      function _transferOwnership(address newOwner) internal virtual {
          address oldOwner = _owner;
          _owner = newOwner;
          emit OwnershipTransferred(oldOwner, newOwner);
      }
  }
  
  // File: contracts/WiseSquirrels.sol
  
  
  pragma solidity ^0.8.22;
  
  
  
  
  
  
  
  
  interface IERC721Burnable is IERC721 {
      function burn(uint256 tokenId) external;
  }
  
  contract WiseSquirrels is Ownable, ERC721A, PaymentSplitter, IERC721Receiver {
  
      using Strings for uint;
  
      string public baseURI;
  
      IERC721Burnable NutsContract = IERC721Burnable (0xBf2998F2e85294f49E389bDd94570683fbffeE23);
  
      uint public  MAX_SUPPLY = 4500;
  
      uint public mutationSalePrice = 0.10 ether;
      uint public wlSalePrice = 0.07 ether;
      uint public publicSalePrice = 0.10 ether;
      uint public discountAmount = 0.02 ether;
  
      bool public publicOn = false;
      bool public whitelistOn = false;
      bool public mutationOn = false;
  
      bytes32 public merkleRootWL;
  
  
      mapping(address => uint) public amountNFTsperWalletWL;
      mapping(address => bool) public freeNFTClaimed;
  
  
      uint private teamLength;
  
      uint96 royaltyFeesInBips;
      address royaltyReceiver;
  
      event Received();
      function onERC721Received(
          address _operator,
          address _from,
          uint256 _tokenId,
          bytes calldata _data
      ) external override returns (bytes4) {
          _operator;
          _from;
          _tokenId;
          _data;
          emit Received();
          return 0x150b7a02;
      }
  
      constructor(uint96 _royaltyFeesInBips, address[] memory _team, uint[] memory _teamShares, string memory _baseURI, address _initialOwner, address _fundsReceiver) ERC721A("Wise Squirrels", "WS")
      PaymentSplitter(_team, _teamShares) Ownable(_initialOwner) {
          baseURI = _baseURI;
          teamLength = _team.length;
          royaltyFeesInBips = _royaltyFeesInBips;
          royaltyReceiver = _fundsReceiver;
      }
  
      modifier callerIsUser() {
          require(tx.origin == msg.sender, "The caller is another contract");
          _;
      }
  
     function whitelistMint(address _account, uint _quantity, bytes32[] calldata _proof) external payable  {
          uint quantityToMint = _quantity;
          require(whitelistOn, "Whitelist sale is not activated");
          require(msg.sender == _account, "Mint with your own wallet.");
          require(isWhiteListed(_account, _proof), "Not whitelisted");
          require(totalSupply() + _quantity <= MAX_SUPPLY, "Max supply exceeded");
          require(msg.value >= wlSalePrice * _quantity, "Not enought funds");
  
          if(amountNFTsperWalletWL[_account] + quantityToMint >= 3 && freeNFTClaimed[_account] == false){
              quantityToMint += 1;
              require(totalSupply() + quantityToMint <= MAX_SUPPLY, "Max supply exceeded");
              freeNFTClaimed[_account] = true;
          }
          amountNFTsperWalletWL[_account] += quantityToMint;
          _safeMint(_account, quantityToMint);
      }
  
      function publicSaleMint(address _account, uint _quantity) external payable  {
          require(publicOn, "Public sale is not activated");
          require(totalSupply() + _quantity <= MAX_SUPPLY, "Max supply exceeded");
          require(msg.value >= publicSalePrice * _quantity, "Not enought funds");
          _safeMint(_account, _quantity);
      }
  
      function mutationMint(address _account, uint[] calldata nfts) external payable  {
          uint finalPrice;
          require(mutationOn, "Mutation sale is not activated");
          require(totalSupply() + 1 <= MAX_SUPPLY, "Max supply exceeded");
          require(nfts.length <= 5, "Only mutate one in a transaction.");
  
          for(uint i = 0; i < nfts.length; i++){
              require(NutsContract.ownerOf(nfts[i]) == _account, "You don't own one of the NFTs.");
          }
          finalPrice = (mutationSalePrice - discountAmount * nfts.length);
          require(msg.value >= finalPrice, "Not enought funds");
  
          for(uint i = 0; i < nfts.length; i++){
             NutsContract.safeTransferFrom(_account, address(this), nfts[i]);
          }
  
          for(uint i = 0; i < nfts.length; i++){
              NutsContract.burn(nfts[i]);
          }
  
          _safeMint(_account, 1);
      }
  
      function burn(uint256 tokenId) external {
          require(
              isApprovedOrOwner(msg.sender, tokenId),
              "Caller is not owner nor approved"
          );
          _burn(tokenId);
      }
      function isApprovedOrOwner(address caller, uint256 tokenId) internal view returns (bool) {
          address owner = ownerOf(tokenId);
          return (caller == owner ||
                  getApproved(tokenId) == caller ||
                  isApprovedForAll(owner, caller));
      }
  
      function gift(address _to, uint _quantity) external onlyOwner {
          require(totalSupply() + _quantity <= MAX_SUPPLY, "Reached max Supply");
          _safeMint(_to, _quantity);
      }
  
      function lowerSupply (uint _MAX_SUPPLY) external onlyOwner{
          require(_MAX_SUPPLY < MAX_SUPPLY, "Cannot increase supply!");
          MAX_SUPPLY = _MAX_SUPPLY;
      }
  
      function setPublicSaleOn(bool _publicOn) external onlyOwner{
          publicOn = _publicOn;
      }
  
      function setWhitelistSaleOn(bool _whitelistOn) external onlyOwner{
          whitelistOn = _whitelistOn;
      }
  
      function setMutationSaleOn(bool _mutationOn) external onlyOwner{
          mutationOn = _mutationOn;
      }
  
      function setWLSalePrice(uint _wlSalePrice) external onlyOwner {
          wlSalePrice = _wlSalePrice;
      }
  
      function setPublicSalePrice(uint _publicSalePrice) external onlyOwner {
          publicSalePrice = _publicSalePrice;
      }
  
      function setMutationSalePrice(uint _mutationSalePrice) external onlyOwner {
          mutationSalePrice = _mutationSalePrice;
      }
  
      function setBaseUri(string memory _baseURI) external onlyOwner {
          baseURI = _baseURI;
      }
  
      function tokenURI(uint _tokenId) public view virtual override returns (string memory) {
          require(_exists(_tokenId), "URI query for nonexistent token");
  
          return string(abi.encodePacked(baseURI, _tokenId.toString(), ".json"));
      }
  
      //Whitelist
      function setMerkleRootWL(bytes32 _merkleRootWL) external onlyOwner {
          merkleRootWL = _merkleRootWL;
      }
  
      function isWhiteListed(address _account, bytes32[] calldata _proof) internal view returns(bool) {
          return _verifyWL(leaf(_account), _proof);
      }
  
      function leaf(address _account) internal pure returns(bytes32) {
          return keccak256(abi.encodePacked(_account));
      }
  
      function _verifyWL(bytes32 _leaf, bytes32[] memory _proof) internal view returns(bool) {
          return MerkleProof.verify(_proof, merkleRootWL, _leaf);
      }
  
      function royaltyInfo (
      uint256 _tokenId,
      uint256 _salePrice
       ) external view returns (
          address receiver,
          uint256 royaltyAmount
       ){
           return (royaltyReceiver, calculateRoyalty(_salePrice));
       }
  
      function calculateRoyalty(uint256 _salePrice) view public returns (uint256){
          return(_salePrice / 10000) * royaltyFeesInBips;
      }
  
      function setRoyaltyInfo (address _receiver, uint96 _royaltyFeesInBips) public onlyOwner {
          royaltyReceiver = _receiver;
          royaltyFeesInBips = _royaltyFeesInBips;
      }
  
      function changeNutsContract(address _newNutsContract) external onlyOwner{
          NutsContract = IERC721Burnable(_newNutsContract);
      }
  
      //ReleaseALL
      function releaseAll() external onlyOwner {
          for(uint i = 0 ; i < teamLength ; i++) {
              release(payable(payee(i)));
          }
      }
  
      receive() override external payable {
          revert('Only if you mint');
      }
  
  }