#include <bits/stdc++.h>
using namespace std;
const int N = 200010;
const int B = 31;
int trie[B * N][2];
int cnt[B * N];
int idx = 1;
void add(int x) {
  int cur = 0;
  for (int i = B - 1; i >= 0; i--) {
    int c = (x >> i) & 1;
    if (trie[cur][c] == -1) trie[cur][c] = idx++;
    cnt[cur]++;
    cur = trie[cur][c];
  }
  cnt[cur]++;
}
void erase(int x) {
  int cur = 0;
  for (int i = B - 1; i >= 0; i--) {
    int c = (x >> i) & 1;
    cnt[cur]--;
    cur = trie[cur][c];
  }
  cnt[cur]--;
}
int query(int x) {
  int cur = 0;
  int ret = 0;
  for (int i = B - 1; i >= 0; i--) {
    int c = (x >> i) & 1;
    if (trie[cur][1 - c] != -1 and cnt[trie[cur][1 - c]] > 0) {
      cur = trie[cur][1 - c];
      ret |= ((1 - c) << i);
    } else {
      cur = trie[cur][c];
      ret |= (c << i);
    }
  }
  return ret;
}
int main() {
  memset(trie, -1, sizeof(trie));
  int q;
  scanf("%d", &q);
  add(0);
  for (int i = 0; i < q; i++) {
    char cmd[3];
    int x;
    scanf("%s %d", cmd, &x);
    if (cmd[0] == '+')
      add(x);
    else if (cmd[0] == '-')
      erase(x);
    else
      printf("%d\n", x ^ query(x));
  }
  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;
const int N = 200010;
const int B = 31;
int trie[B * N][2];
int cnt[B * N];
int idx = 1;
void add(int x) {
  int cur = 0;
  for (int i = B - 1; i >= 0; i--) {
    int c = (x >> i) & 1;
    if (trie[cur][c] == -1) trie[cur][c] = idx++;
    cnt[cur]++;
    cur = trie[cur][c];
  }
  cnt[cur]++;
}
void erase(int x) {
  int cur = 0;
  for (int i = B - 1; i >= 0; i--) {
    int c = (x >> i) & 1;
    cnt[cur]--;
    cur = trie[cur][c];
  }
  cnt[cur]--;
}
int query(int x) {
  int cur = 0;
  int ret = 0;
  for (int i = B - 1; i >= 0; i--) {
    int c = (x >> i) & 1;
    if (trie[cur][1 - c] != -1 and cnt[trie[cur][1 - c]] > 0) {
      cur = trie[cur][1 - c];
      ret |= ((1 - c) << i);
    } else {
      cur = trie[cur][c];
      ret |= (c << i);
    }
  }
  return ret;
}
int main() {
  memset(trie, -1, sizeof(trie));
  int q;
  scanf("%d", &q);
  add(0);
  for (int i = 0; i < q; i++) {
    char cmd[3];
    int x;
    scanf("%s %d", cmd, &x);
    if (cmd[0] == '+')
      add(x);
    else if (cmd[0] == '-')
      erase(x);
    else
      printf("%d\n", x ^ query(x));
  }
  return 0;
}

```