#include <bits/stdc++.h>
using namespace std;
struct trie {
  int pre;
  trie *a[2];
  trie() {
    pre = 0;
    memset(a, 0, sizeof(a));
  }
};
trie *root = new trie();
int x, bin[32];
char op;
inline void add() {
  trie *p = root;
  for (int i = 31; i >= 0; --i) {
    if (!p->a[bin[i]]) p->a[bin[i]] = new trie;
    p = p->a[bin[i]];
    p->pre++;
  }
}
inline void del() {
  trie *p = root;
  for (int i = 31; i >= 0; --i) {
    p = p->a[bin[i]];
    --p->pre;
  }
}
inline int query() {
  trie *p = root;
  char tmp[32];
  for (int i = 31; i >= 0; --i) {
    if (bin[i] == 1) {
      if (p->a[0] != NULL && p->a[0]->pre)
        tmp[31 - i] = '0', p = p->a[0];
      else
        tmp[31 - i] = '1', p = p->a[1];
    } else {
      if (p->a[1] != NULL && p->a[1]->pre)
        tmp[31 - i] = '1', p = p->a[1];
      else
        tmp[31 - i] = '0', p = p->a[0];
    }
  }
  char *End;
  int ans = strtol(tmp, &End, 2);
  return ans ^ x;
}
int main() {
  add();
  int n;
  cin >> n;
  while (n--) {
    cin >> op >> x;
    int val = x;
    for (int i = 0; i < 32; ++i) bin[i] = val % 2, val /= 2;
    if (op == '+') add();
    if (op == '-') del();
    if (op == '?') cout << query() << '\n';
  }
  return 0;
}

### Prompt

Please create a solution in cpp to 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;
struct trie {
  int pre;
  trie *a[2];
  trie() {
    pre = 0;
    memset(a, 0, sizeof(a));
  }
};
trie *root = new trie();
int x, bin[32];
char op;
inline void add() {
  trie *p = root;
  for (int i = 31; i >= 0; --i) {
    if (!p->a[bin[i]]) p->a[bin[i]] = new trie;
    p = p->a[bin[i]];
    p->pre++;
  }
}
inline void del() {
  trie *p = root;
  for (int i = 31; i >= 0; --i) {
    p = p->a[bin[i]];
    --p->pre;
  }
}
inline int query() {
  trie *p = root;
  char tmp[32];
  for (int i = 31; i >= 0; --i) {
    if (bin[i] == 1) {
      if (p->a[0] != NULL && p->a[0]->pre)
        tmp[31 - i] = '0', p = p->a[0];
      else
        tmp[31 - i] = '1', p = p->a[1];
    } else {
      if (p->a[1] != NULL && p->a[1]->pre)
        tmp[31 - i] = '1', p = p->a[1];
      else
        tmp[31 - i] = '0', p = p->a[0];
    }
  }
  char *End;
  int ans = strtol(tmp, &End, 2);
  return ans ^ x;
}
int main() {
  add();
  int n;
  cin >> n;
  while (n--) {
    cin >> op >> x;
    int val = x;
    for (int i = 0; i < 32; ++i) bin[i] = val % 2, val /= 2;
    if (op == '+') add();
    if (op == '-') del();
    if (op == '?') cout << query() << '\n';
  }
  return 0;
}

```