#include <bits/stdc++.h>
using namespace std;
struct node {
  int cnt;
  node* child[2];
  node() {
    cnt = 0;
    for (int i = 0; i < 2; i++) {
      child[i] = nullptr;
    }
  }
};
void addNum(int x, node* cur) {
  for (int i = 31; i >= 0; i--) {
    bool bit = x & (1 << i);
    if (cur->child[bit] == nullptr) {
      cur->child[bit] = new node();
    }
    cur = cur->child[bit];
    cur->cnt++;
  }
}
void delNum(int x, node* root, node* cur, int i) {
  if (i < 0) {
    return;
  }
  bool bit = x & (1 << i);
  delNum(x, root, cur->child[bit], i - 1);
  if (cur->child[bit]->cnt == 1) {
    delete cur->child[bit];
    cur->child[bit] = nullptr;
  } else {
    cur->child[bit]->cnt--;
  }
}
int query(int x, node* cur) {
  int res = 0;
  for (int i = 31; i >= 0; i--) {
    bool bit = x & (1 << i);
    if (cur->child[!bit] != nullptr) {
      res |= (!bit) << i;
      cur = cur->child[!bit];
    } else {
      res |= bit << i;
      cur = cur->child[bit];
    }
  }
  return res;
}
void delTrie(node* cur) {
  for (int i = 0; i < 2; i++) {
    if (cur->child[i] != nullptr) {
      delTrie(cur->child[i]);
    }
  }
  delete cur;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int q;
  cin >> q;
  node* root = new node();
  addNum(0, root);
  while (q--) {
    char c;
    cin >> c;
    int x;
    cin >> x;
    if (c == '+') {
      addNum(x, root);
    } else if (c == '-') {
      delNum(x, root, root, 31);
    } else {
      int res = x ^ query(x, root);
      cout << res << '\n';
    }
  }
  delTrie(root);
  return 0;
}

### Prompt

Construct a CPP code solution to the problem outlined:

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 cnt;
  node* child[2];
  node() {
    cnt = 0;
    for (int i = 0; i < 2; i++) {
      child[i] = nullptr;
    }
  }
};
void addNum(int x, node* cur) {
  for (int i = 31; i >= 0; i--) {
    bool bit = x & (1 << i);
    if (cur->child[bit] == nullptr) {
      cur->child[bit] = new node();
    }
    cur = cur->child[bit];
    cur->cnt++;
  }
}
void delNum(int x, node* root, node* cur, int i) {
  if (i < 0) {
    return;
  }
  bool bit = x & (1 << i);
  delNum(x, root, cur->child[bit], i - 1);
  if (cur->child[bit]->cnt == 1) {
    delete cur->child[bit];
    cur->child[bit] = nullptr;
  } else {
    cur->child[bit]->cnt--;
  }
}
int query(int x, node* cur) {
  int res = 0;
  for (int i = 31; i >= 0; i--) {
    bool bit = x & (1 << i);
    if (cur->child[!bit] != nullptr) {
      res |= (!bit) << i;
      cur = cur->child[!bit];
    } else {
      res |= bit << i;
      cur = cur->child[bit];
    }
  }
  return res;
}
void delTrie(node* cur) {
  for (int i = 0; i < 2; i++) {
    if (cur->child[i] != nullptr) {
      delTrie(cur->child[i]);
    }
  }
  delete cur;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int q;
  cin >> q;
  node* root = new node();
  addNum(0, root);
  while (q--) {
    char c;
    cin >> c;
    int x;
    cin >> x;
    if (c == '+') {
      addNum(x, root);
    } else if (c == '-') {
      delNum(x, root, root, 31);
    } else {
      int res = x ^ query(x, root);
      cout << res << '\n';
    }
  }
  delTrie(root);
  return 0;
}

```