#include <bits/stdc++.h>
using namespace std;
const int INF = 1E9;
multiset<long long> S;
int N;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cin >> N;
  S.insert(0);
  for (long long i = 1; i <= N; i++) {
    char c;
    long long x;
    cin >> c >> x;
    if (c == '+') S.insert(x);
    if (c == '-') S.erase(S.find(x));
    if (c == '?') {
      long long ans = 0;
      for (long long i = 30; i >= 0; i--) {
        multiset<long long>::iterator itb =
            S.lower_bound(ans + (((~(x >> i)) & 1LL) << i));
        multiset<long long>::iterator ite =
            S.upper_bound(ans + (((~(x >> i)) & 1LL) << i) + (1LL << i) - 1LL);
        if (itb == ite)
          ans += (((x >> i) & 1LL) << i);
        else
          ans += (((~(x >> i)) & 1LL) << i);
      }
      cout << (x ^ ans) << endl;
    }
  }
  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 int INF = 1E9;
multiset<long long> S;
int N;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cin >> N;
  S.insert(0);
  for (long long i = 1; i <= N; i++) {
    char c;
    long long x;
    cin >> c >> x;
    if (c == '+') S.insert(x);
    if (c == '-') S.erase(S.find(x));
    if (c == '?') {
      long long ans = 0;
      for (long long i = 30; i >= 0; i--) {
        multiset<long long>::iterator itb =
            S.lower_bound(ans + (((~(x >> i)) & 1LL) << i));
        multiset<long long>::iterator ite =
            S.upper_bound(ans + (((~(x >> i)) & 1LL) << i) + (1LL << i) - 1LL);
        if (itb == ite)
          ans += (((x >> i) & 1LL) << i);
        else
          ans += (((~(x >> i)) & 1LL) << i);
      }
      cout << (x ^ ans) << endl;
    }
  }
  return 0;
}

```