#include <bits/stdc++.h>
using namespace std;
class trie {
 public:
  trie* bit[2];
  long long cnt = 0;
};
trie* head;
void insert(long long first) {
  trie* curr = head;
  for (long long i = 30; i >= 0; i--) {
    long long b = (first >> i) & 1;
    if (!curr->bit[b]) {
      curr->bit[b] = new trie();
    }
    curr = curr->bit[b];
    curr->cnt++;
  }
}
void remove(long long first) {
  trie* curr = head;
  for (long long i = 30; i >= 0; i--) {
    long long b = (first >> i) & 1;
    curr = curr->bit[b];
    curr->cnt--;
  }
}
long long maxxor(long long first) {
  trie* curr = head;
  long long ans = 0;
  for (long long i = 30; i >= 0; i--) {
    long long b = (first >> i) & 1;
    if (curr->bit[!b] and curr->bit[!b]->cnt > 0) {
      ans += (1LL << i);
      curr = curr->bit[!b];
    } else {
      curr = curr->bit[b];
    }
  }
  return ans;
}
void solve() {
  char c;
  cin >> c;
  long long first;
  cin >> first;
  if (c == '+') {
    insert(first);
  } else if (c == '-') {
    remove(first);
  } else if (c == '?') {
    cout << maxxor(first) << '\n';
  }
}
int32_t main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  head = new trie();
  insert(0);
  long long t;
  cin >> t;
  while (t--) {
    solve();
  }
}

### 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;
class trie {
 public:
  trie* bit[2];
  long long cnt = 0;
};
trie* head;
void insert(long long first) {
  trie* curr = head;
  for (long long i = 30; i >= 0; i--) {
    long long b = (first >> i) & 1;
    if (!curr->bit[b]) {
      curr->bit[b] = new trie();
    }
    curr = curr->bit[b];
    curr->cnt++;
  }
}
void remove(long long first) {
  trie* curr = head;
  for (long long i = 30; i >= 0; i--) {
    long long b = (first >> i) & 1;
    curr = curr->bit[b];
    curr->cnt--;
  }
}
long long maxxor(long long first) {
  trie* curr = head;
  long long ans = 0;
  for (long long i = 30; i >= 0; i--) {
    long long b = (first >> i) & 1;
    if (curr->bit[!b] and curr->bit[!b]->cnt > 0) {
      ans += (1LL << i);
      curr = curr->bit[!b];
    } else {
      curr = curr->bit[b];
    }
  }
  return ans;
}
void solve() {
  char c;
  cin >> c;
  long long first;
  cin >> first;
  if (c == '+') {
    insert(first);
  } else if (c == '-') {
    remove(first);
  } else if (c == '?') {
    cout << maxxor(first) << '\n';
  }
}
int32_t main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  head = new trie();
  insert(0);
  long long t;
  cin >> t;
  while (t--) {
    solve();
  }
}

```