#include <bits/stdc++.h>
using namespace std;
struct trie {
  map<char, pair<int, trie>> m;
  void add(const string &s, int p = 0) {
    if (s[p]) m[s[p]].first++, m[s[p]].second.add(s, p + 1);
  }
  void remove(const string &s, int p = 0) {
    if (s[p]) {
      m[s[p]].first--;
      if (!m[s[p]].first)
        m.erase(s[p]);
      else
        m[s[p]].second.remove(s, p + 1);
    }
  }
  int dfs(const string &s, int p = 0) {
    if (!s[p]) return 0;
    char r = s[p] == '0' ? '1' : '0';
    if (m[s[p]].first) {
      return m[s[p]].second.dfs(s, p + 1) | ((s[p] - '0') << (31 - p));
    } else if (s[p] == '0' ? m['1'].first : m['0'].first) {
      return m[r].second.dfs(s, p + 1) | ((r - '0') << (31 - p));
    } else
      return 0;
  }
};
string num2bin(unsigned int x) {
  char str[33] = {};
  for (int i = 0; i < 32; i++) {
    if (x & (1 << i))
      str[31 - i] = '1';
    else
      str[31 - i] = '0';
  }
  return string(str);
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int n;
  cin >> n;
  trie t;
  t.add(num2bin(0));
  for (int i = 0; i < n; i++) {
    char op;
    unsigned int x;
    cin >> op >> x;
    if (op == '+') {
      t.add(num2bin(x));
    } else if (op == '-') {
      t.remove(num2bin(x));
    } else {
      int r = t.dfs(num2bin(~x));
      cout << (r ^ x) << endl;
    }
  }
  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 {
  map<char, pair<int, trie>> m;
  void add(const string &s, int p = 0) {
    if (s[p]) m[s[p]].first++, m[s[p]].second.add(s, p + 1);
  }
  void remove(const string &s, int p = 0) {
    if (s[p]) {
      m[s[p]].first--;
      if (!m[s[p]].first)
        m.erase(s[p]);
      else
        m[s[p]].second.remove(s, p + 1);
    }
  }
  int dfs(const string &s, int p = 0) {
    if (!s[p]) return 0;
    char r = s[p] == '0' ? '1' : '0';
    if (m[s[p]].first) {
      return m[s[p]].second.dfs(s, p + 1) | ((s[p] - '0') << (31 - p));
    } else if (s[p] == '0' ? m['1'].first : m['0'].first) {
      return m[r].second.dfs(s, p + 1) | ((r - '0') << (31 - p));
    } else
      return 0;
  }
};
string num2bin(unsigned int x) {
  char str[33] = {};
  for (int i = 0; i < 32; i++) {
    if (x & (1 << i))
      str[31 - i] = '1';
    else
      str[31 - i] = '0';
  }
  return string(str);
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int n;
  cin >> n;
  trie t;
  t.add(num2bin(0));
  for (int i = 0; i < n; i++) {
    char op;
    unsigned int x;
    cin >> op >> x;
    if (op == '+') {
      t.add(num2bin(x));
    } else if (op == '-') {
      t.remove(num2bin(x));
    } else {
      int r = t.dfs(num2bin(~x));
      cout << (r ^ x) << endl;
    }
  }
  return 0;
}

```