#include <bits/stdc++.h>
using namespace std;
int ra() {
  int x = 0, f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = x * 10 + ch - '0';
    ch = getchar();
  }
  return x * f;
}
map<int, int> mp;
int a[35], q;
long long ans;
void orz(int x) {
  for (int i = 30; i >= 1; i--) a[30 - i + 1] = (x >> i - 1) & 1;
}
void add(int x, int num, int d) {
  if (d > 30) return;
  if (a[d] == 1) {
    mp[num << 1 | 1]++;
    add(x, num << 1 | 1, d + 1);
  } else {
    mp[num << 1]++;
    add(x, num << 1, d + 1);
  }
}
void del(int x, int num, int d) {
  if (d > 30) return;
  if (a[d] == 1)
    mp[num << 1 | 1]--, del(x, num << 1 | 1, d + 1);
  else
    mp[num << 1]--, del(x, num << 1, d + 1);
}
void ask(int x, int num, int d) {
  if (d > 30) return;
  if (a[d] == 1) {
    if (mp[num << 1] != 0) {
      ans += (long long)1 << (30 - d);
      ask(x, num << 1, d + 1);
    } else
      ask(x, num << 1 | 1, d + 1);
  } else {
    if (mp[num << 1 | 1] != 0) {
      ans += (long long)1 << (30 - d);
      ask(x, num << 1 | 1, d + 1);
    } else
      ask(x, num << 1, d + 1);
  }
}
int main() {
  q = ra();
  add(0, 1, 1);
  for (int i = 1; i <= q; i++) {
    char ch[2];
    int x;
    scanf("%s", &ch);
    x = ra();
    orz(x);
    if (ch[0] == '-') del(x, 1, 1);
    if (ch[0] == '+') add(x, 1, 1);
    if (ch[0] == '?') {
      ans = 0;
      ask(x, 1, 1);
      printf("%lld\n", ans);
    }
  }
  return 0;
}

### Prompt

Generate 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;
int ra() {
  int x = 0, f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = x * 10 + ch - '0';
    ch = getchar();
  }
  return x * f;
}
map<int, int> mp;
int a[35], q;
long long ans;
void orz(int x) {
  for (int i = 30; i >= 1; i--) a[30 - i + 1] = (x >> i - 1) & 1;
}
void add(int x, int num, int d) {
  if (d > 30) return;
  if (a[d] == 1) {
    mp[num << 1 | 1]++;
    add(x, num << 1 | 1, d + 1);
  } else {
    mp[num << 1]++;
    add(x, num << 1, d + 1);
  }
}
void del(int x, int num, int d) {
  if (d > 30) return;
  if (a[d] == 1)
    mp[num << 1 | 1]--, del(x, num << 1 | 1, d + 1);
  else
    mp[num << 1]--, del(x, num << 1, d + 1);
}
void ask(int x, int num, int d) {
  if (d > 30) return;
  if (a[d] == 1) {
    if (mp[num << 1] != 0) {
      ans += (long long)1 << (30 - d);
      ask(x, num << 1, d + 1);
    } else
      ask(x, num << 1 | 1, d + 1);
  } else {
    if (mp[num << 1 | 1] != 0) {
      ans += (long long)1 << (30 - d);
      ask(x, num << 1 | 1, d + 1);
    } else
      ask(x, num << 1, d + 1);
  }
}
int main() {
  q = ra();
  add(0, 1, 1);
  for (int i = 1; i <= q; i++) {
    char ch[2];
    int x;
    scanf("%s", &ch);
    x = ra();
    orz(x);
    if (ch[0] == '-') del(x, 1, 1);
    if (ch[0] == '+') add(x, 1, 1);
    if (ch[0] == '?') {
      ans = 0;
      ask(x, 1, 1);
      printf("%lld\n", ans);
    }
  }
  return 0;
}

```