#include <bits/stdc++.h>
using namespace std;
template <typename T>
void out(T x) {
  cout << x << endl;
  exit(0);
}
const int maxn = 1e6 + 5;
int q;
multiset<int> ms;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cin >> q;
  ms.insert(0);
  while (q--) {
    char op;
    int x;
    cin >> op >> x;
    if (op == '+') {
      ms.insert(x);
    } else if (op == '-') {
      ms.erase(ms.find(x));
    } else {
      int cur = 0;
      for (int i = 30; i >= 0; i--) {
        cur = (cur | ((~x) & (1 << i)));
        auto iter = ms.lower_bound(cur);
        if (iter == ms.end() || ((*iter) >> i) != (cur >> i)) {
          cur = cur ^ (1 << i);
        }
      }
      int res = cur ^ x;
      cout << res << '\n';
    }
  }
  return 0;
}

### Prompt

Develop a solution in cpp to the problem described below:

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;
template <typename T>
void out(T x) {
  cout << x << endl;
  exit(0);
}
const int maxn = 1e6 + 5;
int q;
multiset<int> ms;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cin >> q;
  ms.insert(0);
  while (q--) {
    char op;
    int x;
    cin >> op >> x;
    if (op == '+') {
      ms.insert(x);
    } else if (op == '-') {
      ms.erase(ms.find(x));
    } else {
      int cur = 0;
      for (int i = 30; i >= 0; i--) {
        cur = (cur | ((~x) & (1 << i)));
        auto iter = ms.lower_bound(cur);
        if (iter == ms.end() || ((*iter) >> i) != (cur >> i)) {
          cur = cur ^ (1 << i);
        }
      }
      int res = cur ^ x;
      cout << res << '\n';
    }
  }
  return 0;
}

```