#include <bits/stdc++.h>
using namespace std;
unsigned x, l, r, y;
int q;
char qu;
unordered_map<unsigned int, int> cnt;
set<unsigned int> nums;
int main() {
  ios_base::sync_with_stdio(0), cin.tie(nullptr), cout.tie(nullptr);
  cin >> q;
  cnt[0]++;
  nums.insert(0);
  for (int i = 0; i < q; ++i) {
    cin >> qu >> x;
    if (qu == '+') {
      cnt[x]++;
      if (cnt[x] == 1) nums.insert(x);
    } else if (qu == '-') {
      --cnt[x];
      if (cnt[x] == 0) nums.erase(x);
    } else {
      l = 0, r = 4294967295, y = ~x;
      for (int i = 31; i >= 0; --i) {
        if (y & (1 << i)) {
          auto it = nums.lower_bound(l + (1 << i));
          if (it != nums.end() && *it <= r) {
            l += (1 << i);
          } else
            r -= (1 << i);
        } else {
          auto it = nums.lower_bound(l);
          if (it != nums.end() && *it < l + (1 << i)) {
            r -= (1 << i);
          } else
            l += (1 << i);
        }
      }
      cout << (l ^ x) << endl;
    }
  }
}

### Prompt

Please provide a Cpp coded solution to the problem described below:

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;
unsigned x, l, r, y;
int q;
char qu;
unordered_map<unsigned int, int> cnt;
set<unsigned int> nums;
int main() {
  ios_base::sync_with_stdio(0), cin.tie(nullptr), cout.tie(nullptr);
  cin >> q;
  cnt[0]++;
  nums.insert(0);
  for (int i = 0; i < q; ++i) {
    cin >> qu >> x;
    if (qu == '+') {
      cnt[x]++;
      if (cnt[x] == 1) nums.insert(x);
    } else if (qu == '-') {
      --cnt[x];
      if (cnt[x] == 0) nums.erase(x);
    } else {
      l = 0, r = 4294967295, y = ~x;
      for (int i = 31; i >= 0; --i) {
        if (y & (1 << i)) {
          auto it = nums.lower_bound(l + (1 << i));
          if (it != nums.end() && *it <= r) {
            l += (1 << i);
          } else
            r -= (1 << i);
        } else {
          auto it = nums.lower_bound(l);
          if (it != nums.end() && *it < l + (1 << i)) {
            r -= (1 << i);
          } else
            l += (1 << i);
        }
      }
      cout << (l ^ x) << endl;
    }
  }
}

```