#include <bits/stdc++.h>
using namespace std;
const int inf = 1e9;
const long long INF = 1e18;
int q;
struct trie {
  struct trie* node[2];
  bool isend;
  int cnt;
};
struct trie* getnode() {
  struct trie* temp = new struct trie;
  temp->node[0] = temp->node[1] = NULL;
  temp->isend = temp->cnt = 0;
  return temp;
}
struct trie* head = getnode();
void insert(int x) {
  struct trie* temp = head;
  for (int i = 30; i >= 0; i--) {
    int bit = (x >> i) & 1;
    if (temp->node[bit]) {
      temp = temp->node[bit];
      temp->cnt++;
      continue;
    }
    temp->node[bit] = getnode();
    temp = temp->node[bit];
    temp->cnt++;
  }
  temp->isend = 1;
}
int search(int x) {
  int res = 0;
  struct trie* temp = head;
  for (int i = 30; i >= 0; i--) {
    int bit = (x >> i) & 1;
    if (temp->node[!bit] && temp->node[!bit]->cnt > 0) {
      res |= (1 << i);
      temp = temp->node[!bit];
    } else if (temp->node[bit] && temp->node[bit]->cnt > 0) {
      temp = temp->node[bit];
    } else {
      return res;
    }
  }
  return res;
}
void erase(int x) {
  struct trie* temp = head;
  for (int i = 30; i >= 0; i--) {
    int bit = (x >> i) & 1;
    temp = temp->node[bit];
    (temp->cnt)--;
  }
  temp->isend = 0;
}
int main() {
  ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);
  ;
  cin >> q;
  insert(0);
  while (q--) {
    char ch;
    int x;
    cin >> ch >> x;
    if (ch == '+') {
      insert(x);
    } else if (ch == '-') {
      erase(x);
    } else {
      cout << search(x) << "\n";
    }
  }
  return 0;
}

### Prompt

Create a solution in cpp for 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;
const int inf = 1e9;
const long long INF = 1e18;
int q;
struct trie {
  struct trie* node[2];
  bool isend;
  int cnt;
};
struct trie* getnode() {
  struct trie* temp = new struct trie;
  temp->node[0] = temp->node[1] = NULL;
  temp->isend = temp->cnt = 0;
  return temp;
}
struct trie* head = getnode();
void insert(int x) {
  struct trie* temp = head;
  for (int i = 30; i >= 0; i--) {
    int bit = (x >> i) & 1;
    if (temp->node[bit]) {
      temp = temp->node[bit];
      temp->cnt++;
      continue;
    }
    temp->node[bit] = getnode();
    temp = temp->node[bit];
    temp->cnt++;
  }
  temp->isend = 1;
}
int search(int x) {
  int res = 0;
  struct trie* temp = head;
  for (int i = 30; i >= 0; i--) {
    int bit = (x >> i) & 1;
    if (temp->node[!bit] && temp->node[!bit]->cnt > 0) {
      res |= (1 << i);
      temp = temp->node[!bit];
    } else if (temp->node[bit] && temp->node[bit]->cnt > 0) {
      temp = temp->node[bit];
    } else {
      return res;
    }
  }
  return res;
}
void erase(int x) {
  struct trie* temp = head;
  for (int i = 30; i >= 0; i--) {
    int bit = (x >> i) & 1;
    temp = temp->node[bit];
    (temp->cnt)--;
  }
  temp->isend = 0;
}
int main() {
  ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);
  ;
  cin >> q;
  insert(0);
  while (q--) {
    char ch;
    int x;
    cin >> ch >> x;
    if (ch == '+') {
      insert(x);
    } else if (ch == '-') {
      erase(x);
    } else {
      cout << search(x) << "\n";
    }
  }
  return 0;
}

```