#include <bits/stdc++.h>
using namespace std;
struct node {
  bool endmark;
  node *next[2];
  node *pre;
  long long a;
  node() {
    next[0] = NULL;
    next[1] = NULL;
    a = 0;
    pre = NULL;
  }
};
node *root = new node();
void insert1(long long v) {
  root->pre = NULL;
  node *curr = root;
  curr->pre = NULL;
  for (long long i = 31; i >= 0; i--) {
    bool ii = ((1LL << i) & v);
    long long id = (long long)ii;
    if (curr->next[id] == NULL) {
      node *rr = new node();
      rr->pre = curr;
      curr->next[id] = rr;
    }
    curr = curr->next[id];
    curr->a++;
  }
}
void delete1(long long v) {
  node *curr = root;
  for (long long i = 31; i >= 0; i--) {
    bool ii = ((1LL << i) & v);
    int id = ii;
    curr = curr->next[id];
    curr->a--;
  }
  long long i = 1;
  i = 0;
  while (1) {
    bool id = (1LL << i) & v;
    if (curr->pre != NULL) {
      if (curr->a == 0) {
        node *cur = curr->pre;
        delete (curr);
        curr = cur;
        curr->next[id] = NULL;
      } else
        return;
      if (curr->next[!id] == NULL) {
      } else {
        return;
      }
    } else {
      return;
    }
    i++;
  }
}
long long ans = 0;
void search1(long long v) {
  root->pre = NULL;
  node *curr = root;
  for (long long i = 31; i >= 0; i--) {
    bool ii = ((1LL << i) & v);
    long long id = (long long)ii;
    if (curr->next[id] == NULL) {
      if (id == 0) {
        ans += (1LL << i);
      }
      curr = curr->next[!id];
    } else {
      ans += (1LL << i) & v;
      curr = curr->next[id];
    }
  }
}
int main() {
  long long t;
  cin >> t;
  insert1(0);
  while (t--) {
    char c;
    unsigned long long n;
    cin >> c >> n;
    if (c == '+') {
      insert1(n);
    } else if (c == '-') {
      delete1(n);
    } else {
      ans = 0;
      search1(~n);
      cout << (ans ^ n) << endl;
    }
  }
}

### Prompt

Develop a solution in cpp 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;
struct node {
  bool endmark;
  node *next[2];
  node *pre;
  long long a;
  node() {
    next[0] = NULL;
    next[1] = NULL;
    a = 0;
    pre = NULL;
  }
};
node *root = new node();
void insert1(long long v) {
  root->pre = NULL;
  node *curr = root;
  curr->pre = NULL;
  for (long long i = 31; i >= 0; i--) {
    bool ii = ((1LL << i) & v);
    long long id = (long long)ii;
    if (curr->next[id] == NULL) {
      node *rr = new node();
      rr->pre = curr;
      curr->next[id] = rr;
    }
    curr = curr->next[id];
    curr->a++;
  }
}
void delete1(long long v) {
  node *curr = root;
  for (long long i = 31; i >= 0; i--) {
    bool ii = ((1LL << i) & v);
    int id = ii;
    curr = curr->next[id];
    curr->a--;
  }
  long long i = 1;
  i = 0;
  while (1) {
    bool id = (1LL << i) & v;
    if (curr->pre != NULL) {
      if (curr->a == 0) {
        node *cur = curr->pre;
        delete (curr);
        curr = cur;
        curr->next[id] = NULL;
      } else
        return;
      if (curr->next[!id] == NULL) {
      } else {
        return;
      }
    } else {
      return;
    }
    i++;
  }
}
long long ans = 0;
void search1(long long v) {
  root->pre = NULL;
  node *curr = root;
  for (long long i = 31; i >= 0; i--) {
    bool ii = ((1LL << i) & v);
    long long id = (long long)ii;
    if (curr->next[id] == NULL) {
      if (id == 0) {
        ans += (1LL << i);
      }
      curr = curr->next[!id];
    } else {
      ans += (1LL << i) & v;
      curr = curr->next[id];
    }
  }
}
int main() {
  long long t;
  cin >> t;
  insert1(0);
  while (t--) {
    char c;
    unsigned long long n;
    cin >> c >> n;
    if (c == '+') {
      insert1(n);
    } else if (c == '-') {
      delete1(n);
    } else {
      ans = 0;
      search1(~n);
      cout << (ans ^ n) << endl;
    }
  }
}

```