#include <bits/stdc++.h>
using namespace std;
int const LG = 31;
int q;
map<int, int> cnt[LG];
inline void add(int x) {
  int B = 0;
  for (int i = LG - 1; i >= 0; i--) {
    B |= (1 << i);
    cnt[i][x & B]++;
  }
}
inline void rmv(int x) {
  int B = 0;
  for (int i = LG - 1; i >= 0; i--) {
    B |= (1 << i);
    cnt[i][x & B]--;
  }
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cin >> q;
  add(0);
  for (int i = 0; i < q; i++) {
    char c;
    int x;
    cin >> c >> x;
    if (c == '+')
      add(x);
    else if (c == '-')
      rmv(x);
    else {
      int ans = 0, B = 0;
      for (int i = LG - 1; i >= 0; i--) {
        int temp1 = (x & (1 << i)), temp2 = (temp1 ? 0 : (1 << i));
        if (cnt[i][B | temp2]) {
          ans |= (1 << i);
          B |= temp2;
        } else {
          B |= temp1;
        }
      }
      cout << ans << '\n';
    }
  }
}

### 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;
int const LG = 31;
int q;
map<int, int> cnt[LG];
inline void add(int x) {
  int B = 0;
  for (int i = LG - 1; i >= 0; i--) {
    B |= (1 << i);
    cnt[i][x & B]++;
  }
}
inline void rmv(int x) {
  int B = 0;
  for (int i = LG - 1; i >= 0; i--) {
    B |= (1 << i);
    cnt[i][x & B]--;
  }
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cin >> q;
  add(0);
  for (int i = 0; i < q; i++) {
    char c;
    int x;
    cin >> c >> x;
    if (c == '+')
      add(x);
    else if (c == '-')
      rmv(x);
    else {
      int ans = 0, B = 0;
      for (int i = LG - 1; i >= 0; i--) {
        int temp1 = (x & (1 << i)), temp2 = (temp1 ? 0 : (1 << i));
        if (cnt[i][B | temp2]) {
          ans |= (1 << i);
          B |= temp2;
        } else {
          B |= temp1;
        }
      }
      cout << ans << '\n';
    }
  }
}

```