#include <bits/stdc++.h>
using namespace std;
int q;
multiset<int> a;
multiset<int>::iterator it;
bool good(int need, int have, int cntBit) {
  for (int i = 29; i >= cntBit; --i) {
    if (((1 << i) & need) != ((1 << i) & have)) {
      return false;
    }
  }
  return true;
}
int get(int v) {
  int ret = 0;
  for (int i = 29; i >= 0; --i) {
    int need = ((1 << i) & v ? ret : ret ^ (1 << i));
    it = a.lower_bound(need);
    if (it != a.end() && good(need, *it, i)) {
      ret = need;
    } else {
      ret = ((1 << i) & v ? ret ^ (1 << i) : ret);
    }
  }
  return ret;
}
int main() {
  a.insert(0);
  scanf("%d", &q);
  for (int i = 0; i < q; ++i) {
    getchar();
    char ty;
    int x;
    ty = getchar();
    scanf("%d", &x);
    if (ty == '+') {
      a.insert(x);
    } else {
      if (ty == '-') {
        a.erase(a.lower_bound(x));
      } else {
        printf("%d\n", get(x) ^ x);
      }
    }
  }
  return 0;
}

### Prompt

Your task is to create 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;
int q;
multiset<int> a;
multiset<int>::iterator it;
bool good(int need, int have, int cntBit) {
  for (int i = 29; i >= cntBit; --i) {
    if (((1 << i) & need) != ((1 << i) & have)) {
      return false;
    }
  }
  return true;
}
int get(int v) {
  int ret = 0;
  for (int i = 29; i >= 0; --i) {
    int need = ((1 << i) & v ? ret : ret ^ (1 << i));
    it = a.lower_bound(need);
    if (it != a.end() && good(need, *it, i)) {
      ret = need;
    } else {
      ret = ((1 << i) & v ? ret ^ (1 << i) : ret);
    }
  }
  return ret;
}
int main() {
  a.insert(0);
  scanf("%d", &q);
  for (int i = 0; i < q; ++i) {
    getchar();
    char ty;
    int x;
    ty = getchar();
    scanf("%d", &x);
    if (ty == '+') {
      a.insert(x);
    } else {
      if (ty == '-') {
        a.erase(a.lower_bound(x));
      } else {
        printf("%d\n", get(x) ^ x);
      }
    }
  }
  return 0;
}

```