#include <bits/stdc++.h>
using namespace std;
void dbg_out() { cerr << "\b\b]\n"; }
template <typename Head, typename... Tail>
void dbg_out(Head H, Tail... T) {
  cerr << H << ", ";
  dbg_out(T...);
}
struct Trie {
  Trie *bit[2];
  int cnt;
  Trie() {
    for (auto &i : bit) i = nullptr;
    cnt = 0;
  }
  void insert(int x) {
    Trie *curr = this;
    for (int i = 30; i >= 0; --i) {
      bool b = x >> i & 1;
      if (curr->bit[b] == nullptr) curr->bit[b] = new Trie();
      curr = curr->bit[b];
      curr->cnt++;
    }
  }
  int maxxor(int x) {
    Trie *curr = this;
    int ans = 0;
    for (int i = 30; i >= 0; --i) {
      bool b = x >> i & 1;
      if (curr->bit[!b] != nullptr and curr->bit[!b]->cnt > 0) {
        ans |= 1 << i;
        curr = curr->bit[!b];
      } else
        curr = curr->bit[b];
    }
    return ans;
  }
  void remove(int x) {
    Trie *curr = this;
    for (int i = 30; i >= 0; --i) {
      bool b = x >> i & 1;
      curr = curr->bit[b];
      curr->cnt--;
    }
  }
};
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  int q;
  cin >> q;
  Trie t;
  t.insert(0);
  while (q--) {
    char type;
    cin >> type;
    if (type == '+') {
      int x;
      cin >> x;
      t.insert(x);
    } else if (type == '-') {
      int x;
      cin >> x;
      t.remove(x);
    } else {
      int x;
      cin >> x;
      int ans = t.maxxor(x);
      cout << ans << '\n';
    }
  }
  return 0;
}

### Prompt

Please provide a cpp coded solution to the problem described below:

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;
void dbg_out() { cerr << "\b\b]\n"; }
template <typename Head, typename... Tail>
void dbg_out(Head H, Tail... T) {
  cerr << H << ", ";
  dbg_out(T...);
}
struct Trie {
  Trie *bit[2];
  int cnt;
  Trie() {
    for (auto &i : bit) i = nullptr;
    cnt = 0;
  }
  void insert(int x) {
    Trie *curr = this;
    for (int i = 30; i >= 0; --i) {
      bool b = x >> i & 1;
      if (curr->bit[b] == nullptr) curr->bit[b] = new Trie();
      curr = curr->bit[b];
      curr->cnt++;
    }
  }
  int maxxor(int x) {
    Trie *curr = this;
    int ans = 0;
    for (int i = 30; i >= 0; --i) {
      bool b = x >> i & 1;
      if (curr->bit[!b] != nullptr and curr->bit[!b]->cnt > 0) {
        ans |= 1 << i;
        curr = curr->bit[!b];
      } else
        curr = curr->bit[b];
    }
    return ans;
  }
  void remove(int x) {
    Trie *curr = this;
    for (int i = 30; i >= 0; --i) {
      bool b = x >> i & 1;
      curr = curr->bit[b];
      curr->cnt--;
    }
  }
};
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  int q;
  cin >> q;
  Trie t;
  t.insert(0);
  while (q--) {
    char type;
    cin >> type;
    if (type == '+') {
      int x;
      cin >> x;
      t.insert(x);
    } else if (type == '-') {
      int x;
      cin >> x;
      t.remove(x);
    } else {
      int x;
      cin >> x;
      int ans = t.maxxor(x);
      cout << ans << '\n';
    }
  }
  return 0;
}

```