#include <bits/stdc++.h>
using namespace std;
struct Node {
  int cnt0, cnt1, cntEnd;
  Node *nxt0, *nxt1;
  Node() {
    cnt0 = cnt1 = cntEnd = 0;
    nxt0 = nxt1 = nullptr;
  }
};
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  const int MAX_BIT = 31;
  Node *root = new Node();
  auto add = [&](int val) {
    Node *cur = root;
    for (int i = MAX_BIT; i >= 0; --i) {
      int bit = (val >> i) & 1;
      if (bit == 0) {
        if (cur->nxt0 == nullptr) {
          cur->nxt0 = new Node();
        }
        cur->cnt0++;
        cur = cur->nxt0;
      } else {
        if (cur->nxt1 == nullptr) {
          cur->nxt1 = new Node();
        }
        cur->cnt1++;
        cur = cur->nxt1;
      }
      if (i == 0) {
        cur->cntEnd++;
      }
    }
  };
  auto remove = [&](int val) {
    Node *cur = root;
    for (int i = MAX_BIT; i >= 0; --i) {
      int bit = (val >> i) & 1;
      if (bit == 0) {
        cur->cnt0--;
        if (cur->cnt0 == 0) {
          cur->nxt0 = nullptr;
          break;
        }
        cur = cur->nxt0;
      } else {
        cur->cnt1--;
        if (cur->cnt1 == 0) {
          cur->nxt1 = nullptr;
          break;
        }
        cur = cur->nxt1;
      }
      if (i == 0) {
        cur->cntEnd--;
      }
    }
  };
  auto getMax = [&](int val) {
    int ret = val;
    Node *cur = root;
    for (int i = MAX_BIT; i >= 0; --i) {
      int bit = (val >> i) & 1;
      int need = bit ^ 1;
      int x = 0;
      if (need == 0) {
        if (cur->nxt0) {
          cur = cur->nxt0;
        } else if (cur->nxt1) {
          cur = cur->nxt1;
          x = 1;
        }
      } else {
        if (cur->nxt1) {
          cur = cur->nxt1;
          x = 1;
        } else if (cur->nxt0) {
          cur = cur->nxt0;
        }
      }
      val ^= (x << i);
      if (cur->cntEnd) {
        ret = max(ret, val);
      }
    }
    return ret;
  };
  int n;
  cin >> n;
  for (int i = 0; i < n; ++i) {
    char c;
    int val;
    cin >> c >> val;
    if (c == '+') {
      add(val);
    } else if (c == '-') {
      remove(val);
    } else {
      cout << getMax(val) << '\n';
    }
  }
  return 0;
}

### Prompt

Develop a solution in Cpp to the problem described below:

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 Node {
  int cnt0, cnt1, cntEnd;
  Node *nxt0, *nxt1;
  Node() {
    cnt0 = cnt1 = cntEnd = 0;
    nxt0 = nxt1 = nullptr;
  }
};
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  const int MAX_BIT = 31;
  Node *root = new Node();
  auto add = [&](int val) {
    Node *cur = root;
    for (int i = MAX_BIT; i >= 0; --i) {
      int bit = (val >> i) & 1;
      if (bit == 0) {
        if (cur->nxt0 == nullptr) {
          cur->nxt0 = new Node();
        }
        cur->cnt0++;
        cur = cur->nxt0;
      } else {
        if (cur->nxt1 == nullptr) {
          cur->nxt1 = new Node();
        }
        cur->cnt1++;
        cur = cur->nxt1;
      }
      if (i == 0) {
        cur->cntEnd++;
      }
    }
  };
  auto remove = [&](int val) {
    Node *cur = root;
    for (int i = MAX_BIT; i >= 0; --i) {
      int bit = (val >> i) & 1;
      if (bit == 0) {
        cur->cnt0--;
        if (cur->cnt0 == 0) {
          cur->nxt0 = nullptr;
          break;
        }
        cur = cur->nxt0;
      } else {
        cur->cnt1--;
        if (cur->cnt1 == 0) {
          cur->nxt1 = nullptr;
          break;
        }
        cur = cur->nxt1;
      }
      if (i == 0) {
        cur->cntEnd--;
      }
    }
  };
  auto getMax = [&](int val) {
    int ret = val;
    Node *cur = root;
    for (int i = MAX_BIT; i >= 0; --i) {
      int bit = (val >> i) & 1;
      int need = bit ^ 1;
      int x = 0;
      if (need == 0) {
        if (cur->nxt0) {
          cur = cur->nxt0;
        } else if (cur->nxt1) {
          cur = cur->nxt1;
          x = 1;
        }
      } else {
        if (cur->nxt1) {
          cur = cur->nxt1;
          x = 1;
        } else if (cur->nxt0) {
          cur = cur->nxt0;
        }
      }
      val ^= (x << i);
      if (cur->cntEnd) {
        ret = max(ret, val);
      }
    }
    return ret;
  };
  int n;
  cin >> n;
  for (int i = 0; i < n; ++i) {
    char c;
    int val;
    cin >> c >> val;
    if (c == '+') {
      add(val);
    } else if (c == '-') {
      remove(val);
    } else {
      cout << getMax(val) << '\n';
    }
  }
  return 0;
}

```