#include <bits/stdc++.h>
using namespace std;
const int root = 0;
int idxN;
struct NODE {
  int son[2];
  int cnt;
  void init() {
    memset(son, -1, sizeof son);
    cnt = 0;
  }
} node[6000005];
int a[33];
void insert(int x, int f) {
  for (int i = 0; i <= 30; ++i) a[i] = (x >> (30 - i)) & 1;
  int i = 0, now = root;
  while (i <= 30) {
    int id = a[i];
    if (node[now].son[id] == -1) {
      node[now].son[id] = ++idxN;
      node[idxN].init();
    }
    now = node[now].son[id];
    node[now].cnt += f;
    ++i;
  }
}
int query(int x) {
  for (int i = 0; i <= 30; ++i) a[i] = (x >> (30 - i)) & 1;
  int i = 0, now = root, res = 0;
  while (i <= 30) {
    int id = a[i];
    if (node[now].son[1 - id] != -1 && node[node[now].son[1 - id]].cnt > 0) {
      res += 1 << (30 - i);
      now = node[now].son[1 - id];
    } else
      now = node[now].son[id];
    ++i;
  }
  return res;
}
int main() {
  node[root].init(), idxN = 0;
  insert(0, 1);
  int q;
  scanf("%d", &q);
  while (q--) {
    char s[2];
    int x;
    scanf("%s%d", s, &x);
    if (s[0] == '+') {
      insert(x, 1);
    } else if (s[0] == '-') {
      insert(x, -1);
    } else {
      printf("%d\n", query(x));
    }
  }
  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;
const int root = 0;
int idxN;
struct NODE {
  int son[2];
  int cnt;
  void init() {
    memset(son, -1, sizeof son);
    cnt = 0;
  }
} node[6000005];
int a[33];
void insert(int x, int f) {
  for (int i = 0; i <= 30; ++i) a[i] = (x >> (30 - i)) & 1;
  int i = 0, now = root;
  while (i <= 30) {
    int id = a[i];
    if (node[now].son[id] == -1) {
      node[now].son[id] = ++idxN;
      node[idxN].init();
    }
    now = node[now].son[id];
    node[now].cnt += f;
    ++i;
  }
}
int query(int x) {
  for (int i = 0; i <= 30; ++i) a[i] = (x >> (30 - i)) & 1;
  int i = 0, now = root, res = 0;
  while (i <= 30) {
    int id = a[i];
    if (node[now].son[1 - id] != -1 && node[node[now].son[1 - id]].cnt > 0) {
      res += 1 << (30 - i);
      now = node[now].son[1 - id];
    } else
      now = node[now].son[id];
    ++i;
  }
  return res;
}
int main() {
  node[root].init(), idxN = 0;
  insert(0, 1);
  int q;
  scanf("%d", &q);
  while (q--) {
    char s[2];
    int x;
    scanf("%s%d", s, &x);
    if (s[0] == '+') {
      insert(x, 1);
    } else if (s[0] == '-') {
      insert(x, -1);
    } else {
      printf("%d\n", query(x));
    }
  }
  return 0;
}

```