#include <bits/stdc++.h>
using namespace std;
int q;
struct Node {
  Node *sons[2];
  int cnt = 0;
};
Node *root;
void add(int x, int val) {
  Node *cur = root;
  for (int i = 30; i >= 0; i--) {
    cur->cnt += val;
    bool bit = (x & (1 << i)) > 0;
    if (cur->sons[bit] == nullptr) cur->sons[bit] = new Node();
    cur = cur->sons[bit];
  }
  cur->cnt += val;
}
int getMax(int x) {
  Node *cur = root;
  int ans = 0;
  for (int i = 30; i >= 0; i--) {
    bool bit = (x & (1 << i)) > 0;
    bit ^= true;
    if (cur->sons[bit] != nullptr && cur->sons[bit]->cnt)
      ans += (1 << i), cur = cur->sons[bit];
    else
      cur = cur->sons[bit ^ true];
  }
  return ans;
}
int main() {
  root = new Node();
  add(0, 1);
  cin >> q;
  while (q--) {
    char type;
    int x;
    cin >> type >> x;
    if (type == '+') add(x, 1);
    if (type == '-') add(x, -1);
    if (type == '?') cout << getMax(x) << '\n';
  }
  return 0;
}

### 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;
int q;
struct Node {
  Node *sons[2];
  int cnt = 0;
};
Node *root;
void add(int x, int val) {
  Node *cur = root;
  for (int i = 30; i >= 0; i--) {
    cur->cnt += val;
    bool bit = (x & (1 << i)) > 0;
    if (cur->sons[bit] == nullptr) cur->sons[bit] = new Node();
    cur = cur->sons[bit];
  }
  cur->cnt += val;
}
int getMax(int x) {
  Node *cur = root;
  int ans = 0;
  for (int i = 30; i >= 0; i--) {
    bool bit = (x & (1 << i)) > 0;
    bit ^= true;
    if (cur->sons[bit] != nullptr && cur->sons[bit]->cnt)
      ans += (1 << i), cur = cur->sons[bit];
    else
      cur = cur->sons[bit ^ true];
  }
  return ans;
}
int main() {
  root = new Node();
  add(0, 1);
  cin >> q;
  while (q--) {
    char type;
    int x;
    cin >> type >> x;
    if (type == '+') add(x, 1);
    if (type == '-') add(x, -1);
    if (type == '?') cout << getMax(x) << '\n';
  }
  return 0;
}

```