#include <bits/stdc++.h>
using namespace std;
const double PI = acos(-1.0);
const double EPS = 1e-7;
const int N = 2e5 + 1;
int t[2][31 * N];
int cnt[2][31 * N];
int cur = 0;
void ins(long long val) {
  int on = 0;
  for (long long i = 31; i >= 0; --i) {
    int now = (val >> i) & 1LL;
    if (t[now][on] == -1) {
      t[now][on] = ++cur;
    }
    cnt[now][on]++;
    on = t[now][on];
  }
}
void rem(long long val) {
  int on = 0;
  for (long long i = 31; i >= 0; --i) {
    int now = (val >> i) & 1LL;
    cnt[now][on]--;
    on = t[now][on];
  }
}
long long qry(long long val) {
  int on = 0;
  long long r = 0;
  for (long long i = 31; i >= 0; --i) {
    int now = (val >> i) & 1LL;
    int lk = 1 - now;
    if (t[lk][on] != -1 && cnt[lk][on]) {
      r <<= 1;
      r |= 1;
      on = t[lk][on];
    } else {
      r <<= 1;
      on = t[now][on];
    }
  }
  return r;
}
int main() {
  int q;
  scanf("%d", &q);
  memset(t, -1, sizeof t);
  ins(0);
  while (q--) {
    char c;
    long long val;
    scanf(" %c %lld", &c, &val);
    if (c == '+') {
      ins(val);
    } else if (c == '-') {
      rem(val);
    } else {
      printf("%lld\n", max(qry(val), val));
    }
  }
  return 0;
}

### Prompt

Develop a solution in CPP 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 double PI = acos(-1.0);
const double EPS = 1e-7;
const int N = 2e5 + 1;
int t[2][31 * N];
int cnt[2][31 * N];
int cur = 0;
void ins(long long val) {
  int on = 0;
  for (long long i = 31; i >= 0; --i) {
    int now = (val >> i) & 1LL;
    if (t[now][on] == -1) {
      t[now][on] = ++cur;
    }
    cnt[now][on]++;
    on = t[now][on];
  }
}
void rem(long long val) {
  int on = 0;
  for (long long i = 31; i >= 0; --i) {
    int now = (val >> i) & 1LL;
    cnt[now][on]--;
    on = t[now][on];
  }
}
long long qry(long long val) {
  int on = 0;
  long long r = 0;
  for (long long i = 31; i >= 0; --i) {
    int now = (val >> i) & 1LL;
    int lk = 1 - now;
    if (t[lk][on] != -1 && cnt[lk][on]) {
      r <<= 1;
      r |= 1;
      on = t[lk][on];
    } else {
      r <<= 1;
      on = t[now][on];
    }
  }
  return r;
}
int main() {
  int q;
  scanf("%d", &q);
  memset(t, -1, sizeof t);
  ins(0);
  while (q--) {
    char c;
    long long val;
    scanf(" %c %lld", &c, &val);
    if (c == '+') {
      ins(val);
    } else if (c == '-') {
      rem(val);
    } else {
      printf("%lld\n", max(qry(val), val));
    }
  }
  return 0;
}

```