#include <bits/stdc++.h>
using namespace std;
map<int, int> ms0[31];
map<int, int> ms1[31];
int q;
char c;
int x;
int main() {
  int i, j;
  scanf("%d", &q);
  for (j = 30; j >= 0; j--) ms0[j][0]++;
  for (i = 0; i < q; i++) {
    c = '#';
    while (c != '+' && c != '-' && c != '?') scanf("%c", &c);
    scanf("%d", &x);
    if (c == '+') {
      for (j = 0; j <= 30; j++) {
        if (x & (1 << j)) {
          ms1[j][x]++;
          x -= (1 << j);
        } else
          ms0[j][x]++;
      }
    }
    if (c == '-') {
      for (j = 0; j <= 30; j++) {
        if (x & (1 << j)) {
          ms1[j][x]--;
          x -= (1 << j);
        } else
          ms0[j][x]--;
      }
    }
    if (c == '?') {
      int crr = 0;
      for (j = 30; j >= 0; j--) {
        if (!(x & (1 << j))) {
          if (ms1[j][crr + (1 << j)]) crr += (1 << j);
        } else {
          if (!ms0[j][crr]) crr += (1 << j);
        }
      }
      printf("%d\n", x ^ crr);
    }
  }
  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>
using namespace std;
map<int, int> ms0[31];
map<int, int> ms1[31];
int q;
char c;
int x;
int main() {
  int i, j;
  scanf("%d", &q);
  for (j = 30; j >= 0; j--) ms0[j][0]++;
  for (i = 0; i < q; i++) {
    c = '#';
    while (c != '+' && c != '-' && c != '?') scanf("%c", &c);
    scanf("%d", &x);
    if (c == '+') {
      for (j = 0; j <= 30; j++) {
        if (x & (1 << j)) {
          ms1[j][x]++;
          x -= (1 << j);
        } else
          ms0[j][x]++;
      }
    }
    if (c == '-') {
      for (j = 0; j <= 30; j++) {
        if (x & (1 << j)) {
          ms1[j][x]--;
          x -= (1 << j);
        } else
          ms0[j][x]--;
      }
    }
    if (c == '?') {
      int crr = 0;
      for (j = 30; j >= 0; j--) {
        if (!(x & (1 << j))) {
          if (ms1[j][crr + (1 << j)]) crr += (1 << j);
        } else {
          if (!ms0[j][crr]) crr += (1 << j);
        }
      }
      printf("%d\n", x ^ crr);
    }
  }
  return 0;
}

```