#include <bits/stdc++.h>
using namespace std;
int cnt[7000000], child[7000000][2], nxt = 1, q;
void add(int x) {
  int curNode = 0;
  for (int i = 29; i >= 0; i--) {
    int bit = (x >> i) & 1;
    if (!child[curNode][bit]) child[curNode][bit] = nxt++;
    curNode = child[curNode][bit];
    cnt[curNode]++;
  }
}
void del(int x) {
  int curNode = 0;
  for (int i = 29; i >= 0; i--) {
    int bit = (x >> i) & 1;
    curNode = child[curNode][bit];
    cnt[curNode]--;
  }
}
int query(int x) {
  int ans = 0, curNode = 0;
  for (int i = 29; i >= 0; i--) {
    int bit = (x >> i) & 1;
    if (child[curNode][1 - bit] && cnt[child[curNode][1 - bit]]) {
      ans += 1 << i;
      curNode = child[curNode][1 - bit];
    } else {
      curNode = child[curNode][bit];
    }
  }
  return ans;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cin >> q;
  add(0);
  while (q--) {
    char op;
    int num;
    cin >> op >> num;
    if (op == '+')
      add(num);
    else if (op == '-')
      del(num);
    else
      cout << query(num) << '\n';
  }
}

### Prompt

Develop a solution in CPP 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 cnt[7000000], child[7000000][2], nxt = 1, q;
void add(int x) {
  int curNode = 0;
  for (int i = 29; i >= 0; i--) {
    int bit = (x >> i) & 1;
    if (!child[curNode][bit]) child[curNode][bit] = nxt++;
    curNode = child[curNode][bit];
    cnt[curNode]++;
  }
}
void del(int x) {
  int curNode = 0;
  for (int i = 29; i >= 0; i--) {
    int bit = (x >> i) & 1;
    curNode = child[curNode][bit];
    cnt[curNode]--;
  }
}
int query(int x) {
  int ans = 0, curNode = 0;
  for (int i = 29; i >= 0; i--) {
    int bit = (x >> i) & 1;
    if (child[curNode][1 - bit] && cnt[child[curNode][1 - bit]]) {
      ans += 1 << i;
      curNode = child[curNode][1 - bit];
    } else {
      curNode = child[curNode][bit];
    }
  }
  return ans;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cin >> q;
  add(0);
  while (q--) {
    char op;
    int num;
    cin >> op >> num;
    if (op == '+')
      add(num);
    else if (op == '-')
      del(num);
    else
      cout << query(num) << '\n';
  }
}

```