#include <bits/stdc++.h>
const long long N = 100010;
const double INF = 1e18 + 7;
using namespace std;
struct NODE {
  int l, r;
  NODE *lson, *rson;
  NODE() {
    l = r = 0;
    lson = rson = NULL;
  }
};
char type[3];
int a[N], b[N];
NODE *head;
void init(int x) {
  int i;
  for (i = 0; i < 32; i++) {
    a[i] = ((1 << i) & x) > 0 ? 1 : 0;
  }
}
void add() {
  NODE *tmp, *temp;
  tmp = head;
  int i;
  for (i = 31; i >= 0; i--) {
    if (a[i] == 0) {
      tmp->l++;
      if (tmp->lson == NULL) {
        temp = new NODE;
        tmp->lson = temp;
      }
      tmp = tmp->lson;
    } else {
      tmp->r++;
      if (tmp->rson == NULL) {
        temp = new NODE;
        tmp->rson = temp;
      }
      tmp = tmp->rson;
    }
  }
}
void delete_() {
  NODE *tmp;
  tmp = head;
  int i;
  for (i = 31; i >= 0; i--) {
    if (a[i] == 0) {
      tmp->l--;
      tmp = tmp->lson;
    } else {
      tmp->r--;
      tmp = tmp->rson;
    }
  }
}
void solve() {
  NODE *tmp;
  tmp = head;
  int i;
  for (i = 31; i >= 0; i--) {
    if (tmp->l == 0) {
      b[i] = (1 ^ a[i]);
      tmp = tmp->rson;
      continue;
    }
    if (tmp->r == 0) {
      b[i] = (0 ^ a[i]);
      tmp = tmp->lson;
      continue;
    }
    if (a[i] == 0) {
      b[i] = (1 ^ a[i]);
      tmp = tmp->rson;
      continue;
    }
    if (a[i] == 1) {
      b[i] = (0 ^ a[i]);
      tmp = tmp->lson;
      continue;
    }
  }
  int ans = 0;
  for (i = 31; i >= 0; i--) {
    ans *= 2;
    ans += b[i];
  }
  printf("%d\n", ans);
}
int main() {
  head = new NODE;
  int n, tmp;
  scanf("%d", &n);
  memset(a, 0, sizeof(a));
  add();
  while (n-- > 0) {
    scanf("%s%d", type, &tmp);
    init(tmp);
    if (type[0] == '+')
      add();
    else if (type[0] == '-')
      delete_();
    else
      solve();
  }
  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>
const long long N = 100010;
const double INF = 1e18 + 7;
using namespace std;
struct NODE {
  int l, r;
  NODE *lson, *rson;
  NODE() {
    l = r = 0;
    lson = rson = NULL;
  }
};
char type[3];
int a[N], b[N];
NODE *head;
void init(int x) {
  int i;
  for (i = 0; i < 32; i++) {
    a[i] = ((1 << i) & x) > 0 ? 1 : 0;
  }
}
void add() {
  NODE *tmp, *temp;
  tmp = head;
  int i;
  for (i = 31; i >= 0; i--) {
    if (a[i] == 0) {
      tmp->l++;
      if (tmp->lson == NULL) {
        temp = new NODE;
        tmp->lson = temp;
      }
      tmp = tmp->lson;
    } else {
      tmp->r++;
      if (tmp->rson == NULL) {
        temp = new NODE;
        tmp->rson = temp;
      }
      tmp = tmp->rson;
    }
  }
}
void delete_() {
  NODE *tmp;
  tmp = head;
  int i;
  for (i = 31; i >= 0; i--) {
    if (a[i] == 0) {
      tmp->l--;
      tmp = tmp->lson;
    } else {
      tmp->r--;
      tmp = tmp->rson;
    }
  }
}
void solve() {
  NODE *tmp;
  tmp = head;
  int i;
  for (i = 31; i >= 0; i--) {
    if (tmp->l == 0) {
      b[i] = (1 ^ a[i]);
      tmp = tmp->rson;
      continue;
    }
    if (tmp->r == 0) {
      b[i] = (0 ^ a[i]);
      tmp = tmp->lson;
      continue;
    }
    if (a[i] == 0) {
      b[i] = (1 ^ a[i]);
      tmp = tmp->rson;
      continue;
    }
    if (a[i] == 1) {
      b[i] = (0 ^ a[i]);
      tmp = tmp->lson;
      continue;
    }
  }
  int ans = 0;
  for (i = 31; i >= 0; i--) {
    ans *= 2;
    ans += b[i];
  }
  printf("%d\n", ans);
}
int main() {
  head = new NODE;
  int n, tmp;
  scanf("%d", &n);
  memset(a, 0, sizeof(a));
  add();
  while (n-- > 0) {
    scanf("%s%d", type, &tmp);
    init(tmp);
    if (type[0] == '+')
      add();
    else if (type[0] == '-')
      delete_();
    else
      solve();
  }
  return 0;
}

```