#include <bits/stdc++.h>
using namespace std;
const long long int mod = 1e9 + 7;
const long long int inf = 2e9 + 5;
double PI = 3.14159265358979323846;
void solve() {
  int n;
  cin >> n;
  multiset<int> s;
  s.insert(0);
  for (int i = 0; i < n; i++) {
    char c;
    int x;
    cin >> c >> x;
    if (c == '+') {
      s.insert(x);
    } else if (c == '-') {
      s.erase(s.find(x));
    } else {
      int y = ~x;
      int l = 0, r = UINT_MAX;
      for (int k = 31; k >= 0; k--) {
        if (y & (1 << k)) {
          auto it = s.lower_bound(l + (1 << k));
          if (it != s.end() and (*it) <= r) {
            l = l + (1 << k);
          } else {
            r = r - (1 << k);
          }
        } else {
          auto it = s.lower_bound(l);
          if (it != s.end() and (*it) < l + (1 << k)) {
            r = r - (1 << k);
          } else {
            l = l + (1 << k);
          }
        }
      }
      cout << (l ^ x) << "\n";
    }
  }
}
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  solve();
  return 0;
}

### Prompt

Create a solution in cpp for 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 long long int mod = 1e9 + 7;
const long long int inf = 2e9 + 5;
double PI = 3.14159265358979323846;
void solve() {
  int n;
  cin >> n;
  multiset<int> s;
  s.insert(0);
  for (int i = 0; i < n; i++) {
    char c;
    int x;
    cin >> c >> x;
    if (c == '+') {
      s.insert(x);
    } else if (c == '-') {
      s.erase(s.find(x));
    } else {
      int y = ~x;
      int l = 0, r = UINT_MAX;
      for (int k = 31; k >= 0; k--) {
        if (y & (1 << k)) {
          auto it = s.lower_bound(l + (1 << k));
          if (it != s.end() and (*it) <= r) {
            l = l + (1 << k);
          } else {
            r = r - (1 << k);
          }
        } else {
          auto it = s.lower_bound(l);
          if (it != s.end() and (*it) < l + (1 << k)) {
            r = r - (1 << k);
          } else {
            l = l + (1 << k);
          }
        }
      }
      cout << (l ^ x) << "\n";
    }
  }
}
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  solve();
  return 0;
}

```