#include <bits/stdc++.h>
using namespace std;
long long trie[5000001][2], counter[5000001][2], id, root;
long long newTrie() { return ++id; }
long long maxii = 0;
void addTrie(long long x) {
  long long r = root;
  for (long long i = 30; i >= 0; i--) {
    bool first = 0;
    if ((1 << i) & x) {
      first = 1;
    }
    if (trie[r][first]) {
      counter[r][first]++;
      r = trie[r][first];
    } else {
      counter[r][first]++;
      trie[r][first] = newTrie();
      r = trie[r][first];
    }
  }
}
void removeTrie(long long x) {
  long long r = root;
  for (long long i = 30; i >= 0; i--) {
    bool first = 0;
    if ((1 << i) & x) {
      first = 1;
    }
    counter[r][first] -= 1;
    if (counter[r][first] == 0) {
      long long temp = r;
      r = trie[r][first];
      trie[temp][first] = 0;
    } else {
      r = trie[r][first];
    }
  }
}
long long query(long long x) {
  long long r = root;
  long long ans = 0;
  for (long long i = 30; i >= 0; i--) {
    bool first = 1;
    if ((1 << i) & x) {
      first = 0;
    }
    if (trie[r][first]) {
      ans += (1 << i);
      r = trie[r][first];
    } else {
      r = trie[r][!first];
    }
  }
  return ans;
}
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  long long q;
  cin >> q;
  id = 0;
  root = newTrie();
  map<long long, long long> hash;
  addTrie(0);
  while (q--) {
    char ch;
    cin >> ch;
    long long x;
    cin >> x;
    if (ch == '+') {
      if (hash.find(x) != hash.end()) {
        hash[x]++;
      } else {
        addTrie(x);
        hash[x] = 1;
      }
    } else if (ch == '-') {
      if (hash[x] == 1) {
        hash.erase(x);
        removeTrie(x);
      } else {
        hash[x] -= 1;
      }
    } else {
      cout << query(x) << "\n";
    }
  }
  return 0;
}

### Prompt

Your task is to create 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;
long long trie[5000001][2], counter[5000001][2], id, root;
long long newTrie() { return ++id; }
long long maxii = 0;
void addTrie(long long x) {
  long long r = root;
  for (long long i = 30; i >= 0; i--) {
    bool first = 0;
    if ((1 << i) & x) {
      first = 1;
    }
    if (trie[r][first]) {
      counter[r][first]++;
      r = trie[r][first];
    } else {
      counter[r][first]++;
      trie[r][first] = newTrie();
      r = trie[r][first];
    }
  }
}
void removeTrie(long long x) {
  long long r = root;
  for (long long i = 30; i >= 0; i--) {
    bool first = 0;
    if ((1 << i) & x) {
      first = 1;
    }
    counter[r][first] -= 1;
    if (counter[r][first] == 0) {
      long long temp = r;
      r = trie[r][first];
      trie[temp][first] = 0;
    } else {
      r = trie[r][first];
    }
  }
}
long long query(long long x) {
  long long r = root;
  long long ans = 0;
  for (long long i = 30; i >= 0; i--) {
    bool first = 1;
    if ((1 << i) & x) {
      first = 0;
    }
    if (trie[r][first]) {
      ans += (1 << i);
      r = trie[r][first];
    } else {
      r = trie[r][!first];
    }
  }
  return ans;
}
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  long long q;
  cin >> q;
  id = 0;
  root = newTrie();
  map<long long, long long> hash;
  addTrie(0);
  while (q--) {
    char ch;
    cin >> ch;
    long long x;
    cin >> x;
    if (ch == '+') {
      if (hash.find(x) != hash.end()) {
        hash[x]++;
      } else {
        addTrie(x);
        hash[x] = 1;
      }
    } else if (ch == '-') {
      if (hash[x] == 1) {
        hash.erase(x);
        removeTrie(x);
      } else {
        hash[x] -= 1;
      }
    } else {
      cout << query(x) << "\n";
    }
  }
  return 0;
}

```