#include <bits/stdc++.h>
using namespace std;
map<int, int> v;
bool flag = false;
struct Node {
  struct Node *bin[2];
  bool isLeaf;
};
struct Node *getNode() {
  struct Node *temp = (struct Node *)malloc(sizeof(struct Node));
  temp->bin[0] = temp->bin[1] = NULL;
  temp->isLeaf = false;
  return temp;
}
void ini(struct Node *root) {
  struct Node *curr = root;
  for (int i = 30; i >= 0; i--) {
    struct Node *emp = getNode();
    curr->bin[0] = emp;
    curr = emp;
  }
  curr->isLeaf = true;
}
void add(struct Node *root, int val) {
  struct Node *curr = root;
  int temp;
  for (int i = 30; i >= 0; i--) {
    temp = (val >> i) & 1;
    if (!curr->bin[temp]) {
      struct Node *emp = getNode();
      curr->bin[temp] = emp;
    }
    curr = curr->bin[temp];
  }
  curr->isLeaf = true;
}
void hide(struct Node *root, int val, int check) {
  struct Node *curr = root;
  int temp;
  temp = (val >> check) & 1;
  if (check >= 0) hide(curr->bin[temp], val, check - 1);
  if (check < 0) {
    curr->isLeaf = false;
    return;
  }
  if ((curr->bin[temp])->bin[0] == NULL && (curr->bin[temp])->bin[1] == NULL) {
    curr->bin[temp] = NULL;
    delete curr->bin[temp];
    return;
  }
  return;
}
bool show(struct Node *root, int val) {
  struct Node *curr = root;
  int temp;
  for (int i = 30; i >= 0; i--) {
    temp = (val >> i) & 1;
    if (curr->bin[temp] == NULL) {
      cout << "Not Found" << endl;
      return false;
    }
    curr = curr->bin[temp];
  }
  return true;
}
int xorNode(struct Node *root, int val) {
  struct Node *curr = root;
  int temp;
  int res = 0;
  for (int i = 30; i >= 0; i--) {
    temp = (val >> i) & 1;
    if (curr->bin[(temp + 1) % 2] != NULL) {
      res += (1 << i);
      curr = curr->bin[(temp + 1) % 2];
    } else
      curr = curr->bin[temp];
  }
  return res;
}
int main() {
  struct Node *root = getNode();
  add(root, 0);
  int n;
  cin >> n;
  while (n--) {
    char c;
    cin >> c;
    int val;
    cin >> val;
    if (c == '+') {
      if (v[val] == 0) add(root, val);
      v[val]++;
    } else if (c == '-') {
      v[val]--;
      if (v[val] == 0) hide(root, val, 30);
    } else if (c == '?') {
      cout << xorNode(root, val) << endl;
    }
  }
  return 0;
}

### Prompt

Please create a solution in CPP to 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;
map<int, int> v;
bool flag = false;
struct Node {
  struct Node *bin[2];
  bool isLeaf;
};
struct Node *getNode() {
  struct Node *temp = (struct Node *)malloc(sizeof(struct Node));
  temp->bin[0] = temp->bin[1] = NULL;
  temp->isLeaf = false;
  return temp;
}
void ini(struct Node *root) {
  struct Node *curr = root;
  for (int i = 30; i >= 0; i--) {
    struct Node *emp = getNode();
    curr->bin[0] = emp;
    curr = emp;
  }
  curr->isLeaf = true;
}
void add(struct Node *root, int val) {
  struct Node *curr = root;
  int temp;
  for (int i = 30; i >= 0; i--) {
    temp = (val >> i) & 1;
    if (!curr->bin[temp]) {
      struct Node *emp = getNode();
      curr->bin[temp] = emp;
    }
    curr = curr->bin[temp];
  }
  curr->isLeaf = true;
}
void hide(struct Node *root, int val, int check) {
  struct Node *curr = root;
  int temp;
  temp = (val >> check) & 1;
  if (check >= 0) hide(curr->bin[temp], val, check - 1);
  if (check < 0) {
    curr->isLeaf = false;
    return;
  }
  if ((curr->bin[temp])->bin[0] == NULL && (curr->bin[temp])->bin[1] == NULL) {
    curr->bin[temp] = NULL;
    delete curr->bin[temp];
    return;
  }
  return;
}
bool show(struct Node *root, int val) {
  struct Node *curr = root;
  int temp;
  for (int i = 30; i >= 0; i--) {
    temp = (val >> i) & 1;
    if (curr->bin[temp] == NULL) {
      cout << "Not Found" << endl;
      return false;
    }
    curr = curr->bin[temp];
  }
  return true;
}
int xorNode(struct Node *root, int val) {
  struct Node *curr = root;
  int temp;
  int res = 0;
  for (int i = 30; i >= 0; i--) {
    temp = (val >> i) & 1;
    if (curr->bin[(temp + 1) % 2] != NULL) {
      res += (1 << i);
      curr = curr->bin[(temp + 1) % 2];
    } else
      curr = curr->bin[temp];
  }
  return res;
}
int main() {
  struct Node *root = getNode();
  add(root, 0);
  int n;
  cin >> n;
  while (n--) {
    char c;
    cin >> c;
    int val;
    cin >> val;
    if (c == '+') {
      if (v[val] == 0) add(root, val);
      v[val]++;
    } else if (c == '-') {
      v[val]--;
      if (v[val] == 0) hide(root, val, 30);
    } else if (c == '?') {
      cout << xorNode(root, val) << endl;
    }
  }
  return 0;
}

```