#include <bits/stdc++.h>
using namespace std;
char buff[10];
int state[8000000][2];
int cnt[8000000];
int lst = 1;
void ins(int x) {
  int curr = 1;
  for (int i = 31; i >= 0; i--) {
    int b = (((x) >> (i)) & 1);
    if (state[curr][b] == 0) {
      int n_state = ++lst;
      state[curr][b] = n_state;
      cnt[n_state] = 0;
    }
    curr = state[curr][b];
    cnt[curr] += 1;
  }
}
void rmv(int x) {
  int curr = 1;
  for (int i = 31; i >= 0; i--) {
    int b = (((x) >> (i)) & 1);
    if (state[curr][b] == 0) {
      int n_state = ++lst;
      state[curr][b] = n_state;
      cnt[n_state] = 0;
    }
    curr = state[curr][b];
    cnt[curr] -= 1;
  }
}
int query(int x) {
  int curr = 1;
  int ret = 0;
  for (int i = 31; i >= 0; i--) {
    int b = (((x) >> (i)) & 1);
    if (state[curr][b] == 0) {
      int n_state = ++lst;
      state[curr][b] = n_state;
      cnt[n_state] = 0;
    }
    int go = state[curr][b ^ 1];
    int no_go = state[curr][b];
    if (go != 0 && cnt[go] != 0) {
      curr = go;
      ret = ret << 1;
      ret |= 1;
    } else {
      curr = no_go;
      ret = ret << 1;
      ret |= 0;
    }
  }
  return ret;
}
int main() {
  int N;
  scanf("%d", &N);
  ins(0);
  for (int i = 0; i < N; i++) {
    int x;
    scanf("%s%d", buff, &x);
    if (buff[0] == '+') {
      ins(x);
    } else if (buff[0] == '-') {
      rmv(x);
    } else if (buff[0] == '?') {
      int ans = query(x);
      printf("%d\n", ans);
    }
  }
}

### Prompt

Your challenge is to write 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;
char buff[10];
int state[8000000][2];
int cnt[8000000];
int lst = 1;
void ins(int x) {
  int curr = 1;
  for (int i = 31; i >= 0; i--) {
    int b = (((x) >> (i)) & 1);
    if (state[curr][b] == 0) {
      int n_state = ++lst;
      state[curr][b] = n_state;
      cnt[n_state] = 0;
    }
    curr = state[curr][b];
    cnt[curr] += 1;
  }
}
void rmv(int x) {
  int curr = 1;
  for (int i = 31; i >= 0; i--) {
    int b = (((x) >> (i)) & 1);
    if (state[curr][b] == 0) {
      int n_state = ++lst;
      state[curr][b] = n_state;
      cnt[n_state] = 0;
    }
    curr = state[curr][b];
    cnt[curr] -= 1;
  }
}
int query(int x) {
  int curr = 1;
  int ret = 0;
  for (int i = 31; i >= 0; i--) {
    int b = (((x) >> (i)) & 1);
    if (state[curr][b] == 0) {
      int n_state = ++lst;
      state[curr][b] = n_state;
      cnt[n_state] = 0;
    }
    int go = state[curr][b ^ 1];
    int no_go = state[curr][b];
    if (go != 0 && cnt[go] != 0) {
      curr = go;
      ret = ret << 1;
      ret |= 1;
    } else {
      curr = no_go;
      ret = ret << 1;
      ret |= 0;
    }
  }
  return ret;
}
int main() {
  int N;
  scanf("%d", &N);
  ins(0);
  for (int i = 0; i < N; i++) {
    int x;
    scanf("%s%d", buff, &x);
    if (buff[0] == '+') {
      ins(x);
    } else if (buff[0] == '-') {
      rmv(x);
    } else if (buff[0] == '?') {
      int ans = query(x);
      printf("%d\n", ans);
    }
  }
}

```