#include <bits/stdc++.h>
using namespace std;
const long long INF = 99999999999999;
const int inf = 999999999;
int Q;
struct node {
  node *next[2];
  int cnt;
  node() {
    memset(next, 0, sizeof(next));
    cnt = 0;
  }
};
long long ans = 0;
node *p, *root;
void _insert(int x) {
  p = root;
  for (int i = 30; i >= 0; i--) {
    int t = (1 & (x >> i)) ? 1 : 0;
    if (p->next[t] == 0) p->next[t] = new node();
    p = p->next[t];
    p->cnt++;
  }
}
void _delete(int x) {
  p = root;
  for (int i = 30; i >= 0; i--) {
    int t = (1 & (x >> i)) ? 1 : 0;
    p = p->next[t];
    p->cnt--;
  }
}
void _query(int x) {
  p = root;
  ans = 0;
  for (int i = 30; i >= 0; i--) {
    int t = (1 & (x >> i)) ? 0 : 1;
    if (p->next[t] != 0 && p->next[t]->cnt) {
      ans += pow(2, i);
      p = p->next[t];
    } else
      p = p->next[!t];
  }
  printf("%lld\n", ans);
}
int main() {
  while (scanf("%d", &Q) == 1) {
    root = new node();
    _insert(0);
    while (Q--) {
      char op;
      int x;
      getchar();
      scanf("%c%d", &op, &x);
      if (op == '+')
        _insert(x);
      else if (op == '-')
        _delete(x);
      else if (op == '?')
        _query(x);
    }
  }
  return 0;
}

### Prompt

Please formulate 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 long long INF = 99999999999999;
const int inf = 999999999;
int Q;
struct node {
  node *next[2];
  int cnt;
  node() {
    memset(next, 0, sizeof(next));
    cnt = 0;
  }
};
long long ans = 0;
node *p, *root;
void _insert(int x) {
  p = root;
  for (int i = 30; i >= 0; i--) {
    int t = (1 & (x >> i)) ? 1 : 0;
    if (p->next[t] == 0) p->next[t] = new node();
    p = p->next[t];
    p->cnt++;
  }
}
void _delete(int x) {
  p = root;
  for (int i = 30; i >= 0; i--) {
    int t = (1 & (x >> i)) ? 1 : 0;
    p = p->next[t];
    p->cnt--;
  }
}
void _query(int x) {
  p = root;
  ans = 0;
  for (int i = 30; i >= 0; i--) {
    int t = (1 & (x >> i)) ? 0 : 1;
    if (p->next[t] != 0 && p->next[t]->cnt) {
      ans += pow(2, i);
      p = p->next[t];
    } else
      p = p->next[!t];
  }
  printf("%lld\n", ans);
}
int main() {
  while (scanf("%d", &Q) == 1) {
    root = new node();
    _insert(0);
    while (Q--) {
      char op;
      int x;
      getchar();
      scanf("%c%d", &op, &x);
      if (op == '+')
        _insert(x);
      else if (op == '-')
        _delete(x);
      else if (op == '?')
        _query(x);
    }
  }
  return 0;
}

```