#include <bits/stdc++.h>
using namespace std;
int q, all = 1;
int p[10000000][2];
int s[10000000];
void upd(int l, long long x, int v, int id) {
  s[id] += v;
  if (!l) return;
  int d = x >> (l - 1) & 1;
  if (!p[id][d]) p[id][d] = ++all;
  upd(l - 1, x, v, p[id][d]);
  s[id] = s[p[id][0]] + s[p[id][1]];
}
long long query(int l, int x) {
  int id = 1;
  int d;
  long long ans = 0;
  while (l > 0) {
    if (!s[id]) return ans;
    d = x >> (l - 1) & 1 ^ 1;
    if (s[p[id][d]]) {
      ans += 1 << (l - 1);
      id = p[id][d];
    } else
      id = p[id][d ^ 1];
    --l;
  }
  return ans;
}
int main() {
  cin >> q;
  char m;
  long long x;
  while (q--) {
    cin >> m;
    cin >> x;
    if (m == '+') upd(32, x, 1, 1);
    if (m == '-') upd(32, x, -1, 1);
    if (m == '?') cout << max(query(32, x), x) << '\n';
  }
  return 0;
}

### 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;
int q, all = 1;
int p[10000000][2];
int s[10000000];
void upd(int l, long long x, int v, int id) {
  s[id] += v;
  if (!l) return;
  int d = x >> (l - 1) & 1;
  if (!p[id][d]) p[id][d] = ++all;
  upd(l - 1, x, v, p[id][d]);
  s[id] = s[p[id][0]] + s[p[id][1]];
}
long long query(int l, int x) {
  int id = 1;
  int d;
  long long ans = 0;
  while (l > 0) {
    if (!s[id]) return ans;
    d = x >> (l - 1) & 1 ^ 1;
    if (s[p[id][d]]) {
      ans += 1 << (l - 1);
      id = p[id][d];
    } else
      id = p[id][d ^ 1];
    --l;
  }
  return ans;
}
int main() {
  cin >> q;
  char m;
  long long x;
  while (q--) {
    cin >> m;
    cin >> x;
    if (m == '+') upd(32, x, 1, 1);
    if (m == '-') upd(32, x, -1, 1);
    if (m == '?') cout << max(query(32, x), x) << '\n';
  }
  return 0;
}

```