#include <bits/stdc++.h>
using namespace std;
const int N = (int)3e6 + 7;
int Trie[N][2], children[N][2];
char sign;
bitset<31> num;
int new_node = 1;
void Add(bitset<31> num) {
  int node = 0;
  for (int i = 30; i >= 0; --i) {
    if (children[node][num[i]] == 0) children[node][num[i]] = new_node++;
    ++Trie[node][num[i]];
    node = children[node][num[i]];
  }
}
void Delet(bitset<31> num) {
  int node = 0;
  for (int i = 30; i >= 0; --i) {
    --Trie[node][num[i]];
    if (Trie[node][num[i]] == 0) {
      children[node][num[i]] = 0;
      break;
    }
    node = children[node][num[i]];
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  Add(num);
  int n, a;
  cin >> n;
  while (n-- > 0) {
    cin >> sign >> a;
    num = a;
    if (sign == '?') {
      bitset<31> res;
      int node = 0;
      for (int i = 30; i >= 0; --i) {
        if (num[i] == 1) {
          if (children[node][0] != 0) {
            res[i] = 1;
            node = children[node][0];
          } else
            node = children[node][1];
        } else {
          if (children[node][1] != 0) {
            res[i] = 1;
            node = children[node][1];
          } else
            node = children[node][0];
        }
      }
      cout << res.to_ullong() << '\n';
    } else {
      if (sign == '+')
        Add(num);
      else
        Delet(num);
    }
  }
  return 0;
}

### Prompt

Generate a Cpp solution 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;
const int N = (int)3e6 + 7;
int Trie[N][2], children[N][2];
char sign;
bitset<31> num;
int new_node = 1;
void Add(bitset<31> num) {
  int node = 0;
  for (int i = 30; i >= 0; --i) {
    if (children[node][num[i]] == 0) children[node][num[i]] = new_node++;
    ++Trie[node][num[i]];
    node = children[node][num[i]];
  }
}
void Delet(bitset<31> num) {
  int node = 0;
  for (int i = 30; i >= 0; --i) {
    --Trie[node][num[i]];
    if (Trie[node][num[i]] == 0) {
      children[node][num[i]] = 0;
      break;
    }
    node = children[node][num[i]];
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  Add(num);
  int n, a;
  cin >> n;
  while (n-- > 0) {
    cin >> sign >> a;
    num = a;
    if (sign == '?') {
      bitset<31> res;
      int node = 0;
      for (int i = 30; i >= 0; --i) {
        if (num[i] == 1) {
          if (children[node][0] != 0) {
            res[i] = 1;
            node = children[node][0];
          } else
            node = children[node][1];
        } else {
          if (children[node][1] != 0) {
            res[i] = 1;
            node = children[node][1];
          } else
            node = children[node][0];
        }
      }
      cout << res.to_ullong() << '\n';
    } else {
      if (sign == '+')
        Add(num);
      else
        Delet(num);
    }
  }
  return 0;
}

```