#include <bits/stdc++.h>
using namespace std;
int main(int argc, char const *argv[]) {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long q;
  cin >> q;
  char c;
  long long n;
  map<long long, long long> ma;
  ma[0] = 1;
  while (q--) {
    long long res = 0;
    cin >> c >> n;
    if (c == '+') {
      ma[n]++;
    } else if (c == '-') {
      ma[n]--;
      if (ma[n] <= 0) {
        ma.erase(n);
      }
    } else {
      long long res = 0;
      for (int i = 30; i >= 0; i--) {
        long long currbit = 1LL << i;
        long long mask = currbit - 1;
        long long temp = res;
        if (!(n & currbit)) {
          temp = temp | currbit;
        }
        map<long long, long long>::const_iterator it = ma.lower_bound(temp);
        if (it != ma.end() && (it->first & ~mask) == temp)
          res = temp;
        else
          res = temp ^ currbit;
      }
      cout << (res ^ n) << endl;
    }
  }
  return 0;
}

### Prompt

Please provide a CPP coded solution 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;
int main(int argc, char const *argv[]) {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long q;
  cin >> q;
  char c;
  long long n;
  map<long long, long long> ma;
  ma[0] = 1;
  while (q--) {
    long long res = 0;
    cin >> c >> n;
    if (c == '+') {
      ma[n]++;
    } else if (c == '-') {
      ma[n]--;
      if (ma[n] <= 0) {
        ma.erase(n);
      }
    } else {
      long long res = 0;
      for (int i = 30; i >= 0; i--) {
        long long currbit = 1LL << i;
        long long mask = currbit - 1;
        long long temp = res;
        if (!(n & currbit)) {
          temp = temp | currbit;
        }
        map<long long, long long>::const_iterator it = ma.lower_bound(temp);
        if (it != ma.end() && (it->first & ~mask) == temp)
          res = temp;
        else
          res = temp ^ currbit;
      }
      cout << (res ^ n) << endl;
    }
  }
  return 0;
}

```