#include <bits/stdc++.h>
using namespace std;
const long long MAXN = 101 * 1001;
set<long long> s;
map<long long, long long> cnt;
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  s.insert(0);
  long long q, x;
  char ch;
  cin >> q;
  while (q--) {
    cin >> ch >> x;
    if (ch == '+') {
      if (cnt[x] == 0) s.insert(x);
      cnt[x]++;
      ;
    }
    if (ch == '-') {
      cnt[x]--;
      if (cnt[x] == 0) s.erase(x);
    }
    if (ch == '?') {
      long long cur = 0;
      for (long long i = 30; i > -1; i--) {
        if (x & (1 << i)) {
          set<long long>::iterator it = s.lower_bound(cur);
          long long y = *it, f = 0;
          if (y & (1 << i)) f = 1;
          if (f) {
            cur += (1 << i);
          }
        } else {
          set<long long>::iterator it = s.lower_bound(cur + (1 << i));
          if (it == s.end()) continue;
          long long y = *it, f = 0;
          if (y > (cur + (1 << (i + 1))) - 1) f = 1;
          if (f) continue;
          cur += (1 << i);
        }
      }
      cout << (cur ^ x) << '\n';
    }
  }
}

### Prompt

Construct a CPP code solution to the problem outlined:

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 MAXN = 101 * 1001;
set<long long> s;
map<long long, long long> cnt;
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  s.insert(0);
  long long q, x;
  char ch;
  cin >> q;
  while (q--) {
    cin >> ch >> x;
    if (ch == '+') {
      if (cnt[x] == 0) s.insert(x);
      cnt[x]++;
      ;
    }
    if (ch == '-') {
      cnt[x]--;
      if (cnt[x] == 0) s.erase(x);
    }
    if (ch == '?') {
      long long cur = 0;
      for (long long i = 30; i > -1; i--) {
        if (x & (1 << i)) {
          set<long long>::iterator it = s.lower_bound(cur);
          long long y = *it, f = 0;
          if (y & (1 << i)) f = 1;
          if (f) {
            cur += (1 << i);
          }
        } else {
          set<long long>::iterator it = s.lower_bound(cur + (1 << i));
          if (it == s.end()) continue;
          long long y = *it, f = 0;
          if (y > (cur + (1 << (i + 1))) - 1) f = 1;
          if (f) continue;
          cur += (1 << i);
        }
      }
      cout << (cur ^ x) << '\n';
    }
  }
}

```