#include <bits/stdc++.h>
using namespace std;
const int MAXN = 2e5 + 5;
struct trie {
  int child[2], cross[2];
} a[20 * MAXN];
int q, cnt = 0, ans;
void update(int s, int pos, int pre) {
  int x = (s >> pos) % 2;
  if (a[pre].cross[x] == 0 && a[pre].child[x] == 0) a[pre].child[x] = ++cnt;
  a[pre].cross[x]++;
  if (pos == 0) return;
  update(s, pos - 1, a[pre].child[x]);
}
void erase(int s, int pos, int pre) {
  int x = (s >> pos) % 2;
  a[pre].cross[x]--;
  if (pos == 0) return;
  erase(s, pos - 1, a[pre].child[x]);
}
void dfs(int s, int pos, int pre) {
  int x = (s >> pos) % 2;
  if (a[pre].cross[1 - x] > 0) {
    ans ^= (1 << pos);
    x = 1 - x;
  }
  if (pos == 0) return;
  dfs(s, pos - 1, a[pre].child[x]);
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cin >> q;
  update(0, 30, 0);
  while (q--) {
    char itype;
    cin >> itype;
    int x;
    cin >> x;
    if (itype == '+')
      update(x, 30, 0);
    else if (itype == '-')
      erase(x, 30, 0);
    else {
      ans = 0;
      dfs(x, 30, 0);
      cout << ans << "\n";
    }
  }
}

### Prompt

Your task is to create 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;
const int MAXN = 2e5 + 5;
struct trie {
  int child[2], cross[2];
} a[20 * MAXN];
int q, cnt = 0, ans;
void update(int s, int pos, int pre) {
  int x = (s >> pos) % 2;
  if (a[pre].cross[x] == 0 && a[pre].child[x] == 0) a[pre].child[x] = ++cnt;
  a[pre].cross[x]++;
  if (pos == 0) return;
  update(s, pos - 1, a[pre].child[x]);
}
void erase(int s, int pos, int pre) {
  int x = (s >> pos) % 2;
  a[pre].cross[x]--;
  if (pos == 0) return;
  erase(s, pos - 1, a[pre].child[x]);
}
void dfs(int s, int pos, int pre) {
  int x = (s >> pos) % 2;
  if (a[pre].cross[1 - x] > 0) {
    ans ^= (1 << pos);
    x = 1 - x;
  }
  if (pos == 0) return;
  dfs(s, pos - 1, a[pre].child[x]);
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cin >> q;
  update(0, 30, 0);
  while (q--) {
    char itype;
    cin >> itype;
    int x;
    cin >> x;
    if (itype == '+')
      update(x, 30, 0);
    else if (itype == '-')
      erase(x, 30, 0);
    else {
      ans = 0;
      dfs(x, 30, 0);
      cout << ans << "\n";
    }
  }
}

```