#include <bits/stdc++.h>
using namespace std;
const int sze = 200005;
const int mod = 1000000009;
struct node {
  bool endmark;
  node *next[2];
  int cnt;
  node() {
    endmark = false;
    for (int i = 0; i < 2; i++) next[i] = NULL;
    cnt = 0;
  }
};
node *root;
void insertt(int num) {
  node *curr = root;
  for (int i = 31; i >= 0; i--) {
    bool what = (bool)(num & (1 << i));
    int which;
    if (what == 0)
      which = 0;
    else
      which = 1;
    if (curr->next[which] == NULL) {
      curr->next[which] = new node();
    }
    curr = curr->next[which];
    curr->cnt++;
  }
  curr->endmark = true;
}
int searchh(int num) {
  node *curr = root;
  int ret = 0;
  for (int i = 31; i >= 0; i--) {
    bool what = (bool)(num & (1 << i));
    int which;
    if (what == 0)
      which = 0;
    else
      which = 1;
    int inv_which = 1 - which;
    if (curr->next[inv_which] == NULL) {
      curr = curr->next[which];
    } else if (curr->next[inv_which]->cnt) {
      ret = ret + (1 << i);
      curr = curr->next[inv_which];
    }
  }
  return ret;
}
void del(node *cur) {
  for (int i = 0; i < 2; i++) {
    if (cur->next[i]) del(cur->next[i]);
  }
  delete (cur);
}
void delmy(int num) {
  node *curr = root;
  for (int i = 31; i >= 0; i--) {
    bool what = (bool)(num & (1 << i));
    int which;
    if (what == 0)
      which = 0;
    else
      which = 1;
    curr->next[which]->cnt--;
    if (curr->next[which]->cnt == 0) {
      del(curr->next[which]);
      curr->next[which] = NULL;
      break;
    }
    curr = curr->next[which];
  }
}
int main() {
  int q;
  scanf("%d", &q);
  getchar();
  char ch;
  int i;
  int num;
  root = new node();
  insertt(0);
  for (i = 1; i <= q; i++) {
    scanf("%c %d", &ch, &num);
    getchar();
    if (ch == '+') {
      insertt(num);
    } else if (ch == '-') {
      delmy(num);
    } else if (ch == '?') {
      int ret = searchh(num);
      printf("%d\n", ret);
    }
  }
  del(root);
  return 0;
}

### Prompt

Your challenge is to write a CPP solution 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;
const int sze = 200005;
const int mod = 1000000009;
struct node {
  bool endmark;
  node *next[2];
  int cnt;
  node() {
    endmark = false;
    for (int i = 0; i < 2; i++) next[i] = NULL;
    cnt = 0;
  }
};
node *root;
void insertt(int num) {
  node *curr = root;
  for (int i = 31; i >= 0; i--) {
    bool what = (bool)(num & (1 << i));
    int which;
    if (what == 0)
      which = 0;
    else
      which = 1;
    if (curr->next[which] == NULL) {
      curr->next[which] = new node();
    }
    curr = curr->next[which];
    curr->cnt++;
  }
  curr->endmark = true;
}
int searchh(int num) {
  node *curr = root;
  int ret = 0;
  for (int i = 31; i >= 0; i--) {
    bool what = (bool)(num & (1 << i));
    int which;
    if (what == 0)
      which = 0;
    else
      which = 1;
    int inv_which = 1 - which;
    if (curr->next[inv_which] == NULL) {
      curr = curr->next[which];
    } else if (curr->next[inv_which]->cnt) {
      ret = ret + (1 << i);
      curr = curr->next[inv_which];
    }
  }
  return ret;
}
void del(node *cur) {
  for (int i = 0; i < 2; i++) {
    if (cur->next[i]) del(cur->next[i]);
  }
  delete (cur);
}
void delmy(int num) {
  node *curr = root;
  for (int i = 31; i >= 0; i--) {
    bool what = (bool)(num & (1 << i));
    int which;
    if (what == 0)
      which = 0;
    else
      which = 1;
    curr->next[which]->cnt--;
    if (curr->next[which]->cnt == 0) {
      del(curr->next[which]);
      curr->next[which] = NULL;
      break;
    }
    curr = curr->next[which];
  }
}
int main() {
  int q;
  scanf("%d", &q);
  getchar();
  char ch;
  int i;
  int num;
  root = new node();
  insertt(0);
  for (i = 1; i <= q; i++) {
    scanf("%c %d", &ch, &num);
    getchar();
    if (ch == '+') {
      insertt(num);
    } else if (ch == '-') {
      delmy(num);
    } else if (ch == '?') {
      int ret = searchh(num);
      printf("%d\n", ret);
    }
  }
  del(root);
  return 0;
}

```