#include <bits/stdc++.h>
using namespace std;
struct node {
  node *one, *zero;
  long long cnt;
  node() {
    one = NULL;
    zero = NULL;
    cnt = 0LL;
  }
};
void insert(node *root, long long val, long long inc) {
  long long i, j;
  for (i = 30; i >= 0; i--) {
    long long temp = val & (1LL << i);
    if (temp) {
      if (root->one == NULL) root->one = new node();
      root = root->one;
    } else {
      if (root->zero == NULL) root->zero = new node();
      root = root->zero;
    }
    root->cnt += inc;
  }
}
long long query(node *root, long long num) {
  long long i, j, ans = 0;
  for (i = 30; i >= 0; i--) {
    long long temp = num & (1LL << i);
    if (temp) {
      if (root->zero != NULL && root->zero->cnt > 0) {
        ans += (1LL << i);
        root = root->zero;
      } else
        root = root->one;
    } else {
      if (root->one != NULL && root->one->cnt > 0) {
        ans += (1LL << i);
        root = root->one;
      } else
        root = root->zero;
    }
  }
  return ans;
}
int main() {
  node *root = new node();
  insert(root, 0LL, 1LL);
  long long q;
  cin >> q;
  while (q--) {
    char ch;
    long long val;
    cin >> ch >> val;
    if (ch == '+')
      insert(root, val, 1);
    else if (ch == '-')
      insert(root, val, -1);
    else {
      cout << query(root, val) << 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 {
  node *one, *zero;
  long long cnt;
  node() {
    one = NULL;
    zero = NULL;
    cnt = 0LL;
  }
};
void insert(node *root, long long val, long long inc) {
  long long i, j;
  for (i = 30; i >= 0; i--) {
    long long temp = val & (1LL << i);
    if (temp) {
      if (root->one == NULL) root->one = new node();
      root = root->one;
    } else {
      if (root->zero == NULL) root->zero = new node();
      root = root->zero;
    }
    root->cnt += inc;
  }
}
long long query(node *root, long long num) {
  long long i, j, ans = 0;
  for (i = 30; i >= 0; i--) {
    long long temp = num & (1LL << i);
    if (temp) {
      if (root->zero != NULL && root->zero->cnt > 0) {
        ans += (1LL << i);
        root = root->zero;
      } else
        root = root->one;
    } else {
      if (root->one != NULL && root->one->cnt > 0) {
        ans += (1LL << i);
        root = root->one;
      } else
        root = root->zero;
    }
  }
  return ans;
}
int main() {
  node *root = new node();
  insert(root, 0LL, 1LL);
  long long q;
  cin >> q;
  while (q--) {
    char ch;
    long long val;
    cin >> ch >> val;
    if (ch == '+')
      insert(root, val, 1);
    else if (ch == '-')
      insert(root, val, -1);
    else {
      cout << query(root, val) << endl;
    }
  }
}

```