#include <bits/stdc++.h>
typedef struct Trie {
  int sum;
  Trie *next[2];
} Trie;
void Delete(Trie *root) {
  if (root->next[0]) Delete(root->next[0]);
  if (root->next[1]) Delete(root->next[1]);
  delete root;
}
void Create(Trie *root, int a, int c) {
  int now, i;
  Trie *p = root;
  for (i = 30; i >= 0; i--) {
    now = 0;
    if (a & (1 << i)) now = 1;
    if (p->next[now] == NULL) {
      Trie *temp = new Trie;
      temp->next[0] = temp->next[1] = NULL;
      temp->sum = 0;
      p->next[now] = temp;
    }
    p = p->next[now];
    p->sum += c;
  }
}
int Query(Trie *root, int k) {
  int now, i, ans = 0;
  Trie *p = root;
  for (i = 30; i >= 0; i--) {
    now = 0;
    if (k & (1 << i)) now = 1;
    if (p->next[now ^ 1] && p->next[now ^ 1]->sum > 0) {
      ans += (1 << i);
      p = p->next[now ^ 1];
    } else
      p = p->next[now];
  }
  return ans;
}
int main(void) {
  int q, a;
  char ch;
  scanf("%d", &q);
  Trie *root = new Trie;
  root->next[0] = root->next[1] = NULL;
  root->sum = 0;
  Create(root, 0, 1);
  while (q--) {
    scanf(" %c%d", &ch, &a);
    if (ch == '+') Create(root, a, 1);
    if (ch == '-') Create(root, a, -1);
    if (ch == '?') printf("%d\n", Query(root, a));
  }
  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>
typedef struct Trie {
  int sum;
  Trie *next[2];
} Trie;
void Delete(Trie *root) {
  if (root->next[0]) Delete(root->next[0]);
  if (root->next[1]) Delete(root->next[1]);
  delete root;
}
void Create(Trie *root, int a, int c) {
  int now, i;
  Trie *p = root;
  for (i = 30; i >= 0; i--) {
    now = 0;
    if (a & (1 << i)) now = 1;
    if (p->next[now] == NULL) {
      Trie *temp = new Trie;
      temp->next[0] = temp->next[1] = NULL;
      temp->sum = 0;
      p->next[now] = temp;
    }
    p = p->next[now];
    p->sum += c;
  }
}
int Query(Trie *root, int k) {
  int now, i, ans = 0;
  Trie *p = root;
  for (i = 30; i >= 0; i--) {
    now = 0;
    if (k & (1 << i)) now = 1;
    if (p->next[now ^ 1] && p->next[now ^ 1]->sum > 0) {
      ans += (1 << i);
      p = p->next[now ^ 1];
    } else
      p = p->next[now];
  }
  return ans;
}
int main(void) {
  int q, a;
  char ch;
  scanf("%d", &q);
  Trie *root = new Trie;
  root->next[0] = root->next[1] = NULL;
  root->sum = 0;
  Create(root, 0, 1);
  while (q--) {
    scanf(" %c%d", &ch, &a);
    if (ch == '+') Create(root, a, 1);
    if (ch == '-') Create(root, a, -1);
    if (ch == '?') printf("%d\n", Query(root, a));
  }
  return 0;
}

```