#include <bits/stdc++.h>
using namespace std;
const int CMXS = 30, MAXS = 200000 * 18 + 123;
int q, a[3][MAXS], nxt = 0;
bitset<CMXS> b;
int main() {
  cin >> q;
  for (int i = 0; i < 2; i++)
    for (int j = 0; j < MAXS; j++) a[i][j] = -1;
  for (int i = CMXS - 1, v = 0; (~i ? true : (a[2][v]++, false));
       (~a[b[i]][v] ? v = a[b[i]][v] : v = a[b[i]][v] = ++nxt), i--)
    a[2][v]++;
  while (q--) {
    char c;
    int x;
    cin >> c >> x;
    if (c == '+') {
      b = x;
      for (int i = CMXS - 1, v = 0; (~i ? true : (a[2][v]++, false));
           (~a[b[i]][v] ? v = a[b[i]][v] : v = a[b[i]][v] = ++nxt), i--)
        a[2][v]++;
    }
    if (c == '-') {
      b = x;
      for (int i = CMXS - 1, v = 0; (~i ? true : (a[2][v]--, false));
           v = a[b[i]][v], i--)
        a[2][v]--;
    }
    if (c == '?') {
      b = x;
      bitset<CMXS> f;
      for (int i = CMXS - 1, v = 0; ~i; i--)
        if (~a[1 - b[i]][v] && a[2][a[1 - b[i]][v]] > 0) {
          v = a[1 - b[i]][v];
          f[i] = 1;
        } else
          v = a[b[i]][v];
      cout << f.to_ulong() << '\n';
    }
  }
  return 0;
}

### Prompt

Create a solution in CPP for 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 CMXS = 30, MAXS = 200000 * 18 + 123;
int q, a[3][MAXS], nxt = 0;
bitset<CMXS> b;
int main() {
  cin >> q;
  for (int i = 0; i < 2; i++)
    for (int j = 0; j < MAXS; j++) a[i][j] = -1;
  for (int i = CMXS - 1, v = 0; (~i ? true : (a[2][v]++, false));
       (~a[b[i]][v] ? v = a[b[i]][v] : v = a[b[i]][v] = ++nxt), i--)
    a[2][v]++;
  while (q--) {
    char c;
    int x;
    cin >> c >> x;
    if (c == '+') {
      b = x;
      for (int i = CMXS - 1, v = 0; (~i ? true : (a[2][v]++, false));
           (~a[b[i]][v] ? v = a[b[i]][v] : v = a[b[i]][v] = ++nxt), i--)
        a[2][v]++;
    }
    if (c == '-') {
      b = x;
      for (int i = CMXS - 1, v = 0; (~i ? true : (a[2][v]--, false));
           v = a[b[i]][v], i--)
        a[2][v]--;
    }
    if (c == '?') {
      b = x;
      bitset<CMXS> f;
      for (int i = CMXS - 1, v = 0; ~i; i--)
        if (~a[1 - b[i]][v] && a[2][a[1 - b[i]][v]] > 0) {
          v = a[1 - b[i]][v];
          f[i] = 1;
        } else
          v = a[b[i]][v];
      cout << f.to_ulong() << '\n';
    }
  }
  return 0;
}

```