#include <bits/stdc++.h>
using namespace std;
unsigned int x, MSB = 1 << 30, IND = 1;
struct Tri {
  bool isZero = false, isOne = false, B = false;
  int zero, one, num = 0;
};
Tri node[10000000];
void change(int add) {
  unsigned int B = MSB, b = MSB << 1, ind = 0;
  while (b) {
    node[ind].num += add;
    if (x & B) {
      if (!node[ind].isOne) {
        node[ind].isOne = true;
        node[IND].B = true;
        node[ind].one = IND++;
      }
      ind = node[ind].one;
    } else {
      if (!node[ind].isZero) {
        node[ind].isZero = true;
        node[IND].B = false;
        node[ind].zero = IND++;
      }
      ind = node[ind].zero;
    }
    B = B >> 1;
    b = b >> 1;
  }
}
int solve() {
  unsigned int B = MSB, b = MSB << 1, ind = 0, num = 0;
  while (b) {
    if (node[ind].B) num++;
    if (x & B) {
      if (node[ind].isZero && node[node[ind].zero].num) {
        ind = node[ind].zero;
      } else {
        ind = node[ind].one;
      }
    } else {
      if (node[ind].isOne && node[node[ind].one].num) {
        ind = node[ind].one;
      } else {
        ind = node[ind].zero;
      }
    }
    B = B >> 1;
    b = b >> 1;
    num = num << 1;
  }
  num = num >> 1;
  return x ^ num;
}
int main() {
  char c;
  int q;
  change(1);
  cin >> q;
  while (q--) {
    cin >> c;
    cin >> x;
    if (c == '+') {
      change(1);
    } else if (c == '-') {
      change(-1);
    } else {
      cout << solve() << endl;
    }
  }
  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;
unsigned int x, MSB = 1 << 30, IND = 1;
struct Tri {
  bool isZero = false, isOne = false, B = false;
  int zero, one, num = 0;
};
Tri node[10000000];
void change(int add) {
  unsigned int B = MSB, b = MSB << 1, ind = 0;
  while (b) {
    node[ind].num += add;
    if (x & B) {
      if (!node[ind].isOne) {
        node[ind].isOne = true;
        node[IND].B = true;
        node[ind].one = IND++;
      }
      ind = node[ind].one;
    } else {
      if (!node[ind].isZero) {
        node[ind].isZero = true;
        node[IND].B = false;
        node[ind].zero = IND++;
      }
      ind = node[ind].zero;
    }
    B = B >> 1;
    b = b >> 1;
  }
}
int solve() {
  unsigned int B = MSB, b = MSB << 1, ind = 0, num = 0;
  while (b) {
    if (node[ind].B) num++;
    if (x & B) {
      if (node[ind].isZero && node[node[ind].zero].num) {
        ind = node[ind].zero;
      } else {
        ind = node[ind].one;
      }
    } else {
      if (node[ind].isOne && node[node[ind].one].num) {
        ind = node[ind].one;
      } else {
        ind = node[ind].zero;
      }
    }
    B = B >> 1;
    b = b >> 1;
    num = num << 1;
  }
  num = num >> 1;
  return x ^ num;
}
int main() {
  char c;
  int q;
  change(1);
  cin >> q;
  while (q--) {
    cin >> c;
    cin >> x;
    if (c == '+') {
      change(1);
    } else if (c == '-') {
      change(-1);
    } else {
      cout << solve() << endl;
    }
  }
  return 0;
}

```