#include <bits/stdc++.h>
using namespace std;
struct TreeNode {
  int count;
  TreeNode* left;
  TreeNode* right;
  TreeNode(int x) {
    count = x;
    left = NULL;
    right = NULL;
  }
};
void add(TreeNode* root, int val) {
  TreeNode* current = root;
  for (int i = 29; i >= 0; i--) {
    if ((val & (1 << i)) == (1 << i)) {
      if (current->right == NULL)
        current->right = new TreeNode(1);
      else
        current->right->count++;
      current = current->right;
      continue;
    } else {
      if (current->left == NULL)
        current->left = new TreeNode(1);
      else
        current->left->count++;
      current = current->left;
      continue;
    }
  }
}
void remove(TreeNode* root, int val) {
  TreeNode* current = root;
  for (int i = 29; i >= 0; i--) {
    if ((val & (1 << i)) == (1 << i)) {
      current->right->count--;
      current = current->right;
      continue;
    } else {
      current->left->count--;
      current = current->left;
    }
  }
}
long long query(TreeNode* root, int val) {
  TreeNode* current = root;
  long long res = 0;
  for (int i = 29; i >= 0; i--) {
    if ((current->left == NULL || current->left->count == 0) &&
        (current->right == NULL || current->right->count == 0))
      break;
    if ((val & (1 << i)) == (1 << i)) {
      if (current->left != NULL && current->left->count > 0) {
        res += (1 << i);
        current = current->left;
        continue;
      } else {
        current = current->right;
        continue;
      }
    } else {
      if (current->right != NULL && current->right->count > 0) {
        res += (1 << i);
        current = current->right;
        continue;
      } else {
        current = current->left;
        continue;
      }
    }
  }
  return res;
}
int main() {
  int q;
  cin >> q;
  TreeNode* root = new TreeNode(1);
  add(root, 0);
  for (int i = 0; i < q; i++) {
    char type;
    int val;
    cin >> type >> val;
    if (type == '+')
      add(root, val);
    else if (type == '-')
      remove(root, val);
    else {
      long long res = query(root, val);
      cout << res << "\n";
    }
  }
  return 0;
}

### Prompt

Create a solution in CPP for the following problem:

Author has gone out of the stories about Vasiliy, so here is just a formal task description.

You are given q queries and a multiset A, initially containing only integer 0. There are three types of queries:

  1. "+ x" — add integer x to multiset A.
  2. "- x" — erase one occurrence of integer x from multiset A. It's guaranteed that at least one x is present in the multiset A before this query.
  3. "? x" — you are given integer x and need to compute the value <image>, i.e. the maximum value of bitwise exclusive OR (also know as XOR) of integer x and some integer y from the multiset A.



Multiset is a set, where equal elements are allowed.

Input

The first line of the input contains a single integer q (1 ≤ q ≤ 200 000) — the number of queries Vasiliy has to perform.

Each of the following q lines of the input contains one of three characters '+', '-' or '?' and an integer xi (1 ≤ xi ≤ 109). It's guaranteed that there is at least one query of the third type.

Note, that the integer 0 will always be present in the set A.

Output

For each query of the type '?' print one integer — the maximum value of bitwise exclusive OR (XOR) of integer xi and some integer from the multiset A.

Example

Input

10
+ 8
+ 9
+ 11
+ 6
+ 1
? 3
- 8
? 3
? 8
? 11


Output

11
10
14
13

Note

After first five operations multiset A contains integers 0, 8, 9, 11, 6 and 1.

The answer for the sixth query is integer <image> — maximum among integers <image>, <image>, <image>, <image> and <image>.

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
struct TreeNode {
  int count;
  TreeNode* left;
  TreeNode* right;
  TreeNode(int x) {
    count = x;
    left = NULL;
    right = NULL;
  }
};
void add(TreeNode* root, int val) {
  TreeNode* current = root;
  for (int i = 29; i >= 0; i--) {
    if ((val & (1 << i)) == (1 << i)) {
      if (current->right == NULL)
        current->right = new TreeNode(1);
      else
        current->right->count++;
      current = current->right;
      continue;
    } else {
      if (current->left == NULL)
        current->left = new TreeNode(1);
      else
        current->left->count++;
      current = current->left;
      continue;
    }
  }
}
void remove(TreeNode* root, int val) {
  TreeNode* current = root;
  for (int i = 29; i >= 0; i--) {
    if ((val & (1 << i)) == (1 << i)) {
      current->right->count--;
      current = current->right;
      continue;
    } else {
      current->left->count--;
      current = current->left;
    }
  }
}
long long query(TreeNode* root, int val) {
  TreeNode* current = root;
  long long res = 0;
  for (int i = 29; i >= 0; i--) {
    if ((current->left == NULL || current->left->count == 0) &&
        (current->right == NULL || current->right->count == 0))
      break;
    if ((val & (1 << i)) == (1 << i)) {
      if (current->left != NULL && current->left->count > 0) {
        res += (1 << i);
        current = current->left;
        continue;
      } else {
        current = current->right;
        continue;
      }
    } else {
      if (current->right != NULL && current->right->count > 0) {
        res += (1 << i);
        current = current->right;
        continue;
      } else {
        current = current->left;
        continue;
      }
    }
  }
  return res;
}
int main() {
  int q;
  cin >> q;
  TreeNode* root = new TreeNode(1);
  add(root, 0);
  for (int i = 0; i < q; i++) {
    char type;
    int val;
    cin >> type >> val;
    if (type == '+')
      add(root, val);
    else if (type == '-')
      remove(root, val);
    else {
      long long res = query(root, val);
      cout << res << "\n";
    }
  }
  return 0;
}

```