#include <bits/stdc++.h>
using namespace std;
typedef struct Trie {
  Trie *next[2];
  int ans;
} * trie;
Trie *creat() {
  Trie *rt = new Trie();
  for (int i = 0; i < 2; i++) rt->next[i] = NULL;
  rt->ans = 0;
  return rt;
}
void inser(int x, int y, trie root) {
  Trie *rt = root;
  for (int i = 30; i >= 0; i--) {
    int id = x >> i & 1;
    if (rt->next[id] == NULL) {
      rt->next[id] = creat();
    }
    rt = rt->next[id];
    rt->ans += y;
  }
}
int query(int x, trie root) {
  Trie *rt = root;
  int sum = 0;
  for (int i = 30; i >= 0; i--) {
    int id = x >> i & 1;
    id = id ^ 1;
    if (rt->next[id] != NULL && rt->next[id]->ans) {
      sum += (1 << i);
      rt = rt->next[id];
    } else {
      rt = rt->next[id ^ 1];
    }
  }
  return sum;
}
char s[2];
int main() {
  trie root = creat();
  inser(0, 1, root);
  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; i++) {
    int x;
    scanf("%s%d", s, &x);
    if (s[0] != '?')
      inser(x, (s[0] == '+') ? 1 : -1, root);
    else
      printf("%d\n", query(x, root));
  }
  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;
typedef struct Trie {
  Trie *next[2];
  int ans;
} * trie;
Trie *creat() {
  Trie *rt = new Trie();
  for (int i = 0; i < 2; i++) rt->next[i] = NULL;
  rt->ans = 0;
  return rt;
}
void inser(int x, int y, trie root) {
  Trie *rt = root;
  for (int i = 30; i >= 0; i--) {
    int id = x >> i & 1;
    if (rt->next[id] == NULL) {
      rt->next[id] = creat();
    }
    rt = rt->next[id];
    rt->ans += y;
  }
}
int query(int x, trie root) {
  Trie *rt = root;
  int sum = 0;
  for (int i = 30; i >= 0; i--) {
    int id = x >> i & 1;
    id = id ^ 1;
    if (rt->next[id] != NULL && rt->next[id]->ans) {
      sum += (1 << i);
      rt = rt->next[id];
    } else {
      rt = rt->next[id ^ 1];
    }
  }
  return sum;
}
char s[2];
int main() {
  trie root = creat();
  inser(0, 1, root);
  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; i++) {
    int x;
    scanf("%s%d", s, &x);
    if (s[0] != '?')
      inser(x, (s[0] == '+') ? 1 : -1, root);
    else
      printf("%d\n", query(x, root));
  }
  return 0;
}

```