#include <bits/stdc++.h>
using namespace std;
struct Trie {
  Trie() : Children(2) {}
  void Add(unsigned int x, int depth) {
    unsigned int key = (x >> depth) & 1;
    Children[key].second++;
    if (depth == 0) return;
    if (!Children[key].first) {
      Children[key].first.reset(new Trie());
    }
    Children[key].first->Add(x, depth - 1);
  }
  void Delete(unsigned int x, int depth) {
    unsigned int key = (x >> depth) & 1;
    if (--Children[key].second == 0) {
      Children[key].first.reset(nullptr);
    } else if (depth > 0) {
      Children[key].first->Delete(x, depth - 1);
    }
  }
  size_t FindMax(unsigned int x, int depth) {
    unsigned int key = (x >> depth) & 1;
    size_t nextKey = Children[key ^ 1].second ? (key ^ 1) : key;
    size_t res = (nextKey ^ key) << depth;
    if (depth) {
      size_t m = Children[nextKey].first->FindMax(x, depth - 1);
      res |= m;
    }
    return res;
  }
  vector<std::pair<std::unique_ptr<Trie>, int>> Children;
};
int main() {
  unsigned int n;
  cin >> n;
  Trie trie;
  trie.Add(0, 31);
  for (int i = 0; i < n; ++i) {
    unsigned int x;
    char c;
    cin >> c >> x;
    if (c == '+') {
      trie.Add(x, 31);
    } else if (c == '-') {
      trie.Delete(x, 31);
    } else {
      printf("%lu\n", trie.FindMax(x, 31));
    }
  }
  return 0;
}

### Prompt

In Cpp, your task is to solve 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;
struct Trie {
  Trie() : Children(2) {}
  void Add(unsigned int x, int depth) {
    unsigned int key = (x >> depth) & 1;
    Children[key].second++;
    if (depth == 0) return;
    if (!Children[key].first) {
      Children[key].first.reset(new Trie());
    }
    Children[key].first->Add(x, depth - 1);
  }
  void Delete(unsigned int x, int depth) {
    unsigned int key = (x >> depth) & 1;
    if (--Children[key].second == 0) {
      Children[key].first.reset(nullptr);
    } else if (depth > 0) {
      Children[key].first->Delete(x, depth - 1);
    }
  }
  size_t FindMax(unsigned int x, int depth) {
    unsigned int key = (x >> depth) & 1;
    size_t nextKey = Children[key ^ 1].second ? (key ^ 1) : key;
    size_t res = (nextKey ^ key) << depth;
    if (depth) {
      size_t m = Children[nextKey].first->FindMax(x, depth - 1);
      res |= m;
    }
    return res;
  }
  vector<std::pair<std::unique_ptr<Trie>, int>> Children;
};
int main() {
  unsigned int n;
  cin >> n;
  Trie trie;
  trie.Add(0, 31);
  for (int i = 0; i < n; ++i) {
    unsigned int x;
    char c;
    cin >> c >> x;
    if (c == '+') {
      trie.Add(x, 31);
    } else if (c == '-') {
      trie.Delete(x, 31);
    } else {
      printf("%lu\n", trie.FindMax(x, 31));
    }
  }
  return 0;
}

```