#include <bits/stdc++.h>
using namespace std;
int Trie[7000001][2], sz = 0, A[7000001];
void insert(long long int a) {
  int cur = 0;
  A[cur]++;
  for (int i = 31; i >= 0; i--) {
    int d = (a & (1ll << i)) ? 1 : 0;
    if (Trie[cur][d] == 0) {
      Trie[cur][d] = ++sz;
    }
    cur = Trie[cur][d];
    A[cur]++;
  }
}
void del(long long int a) {
  int cur = 0;
  for (int i = 31; i >= 0; i--) {
    int d = (a & (1ll << i)) ? 1 : 0;
    A[cur]--;
    cur = Trie[cur][d];
  }
  A[cur]--;
}
long long int query(long long int a) {
  long long int ans = 0;
  int cur = 0;
  if (A[cur] == 0) return a;
  for (int i = 31; i >= 0; i--) {
    int d = (a & (1ll << i)) ? 1 : 0;
    d = 1 - d;
    if (Trie[cur][d] != 0 && (A[Trie[cur][d]] != 0)) {
      cur = Trie[cur][d];
      ans = ans | (1ll << i);
    } else {
      cur = Trie[cur][1 - d];
    }
  }
  return max(a, ans);
}
int main() {
  long long int q;
  cin >> q;
  long long int a;
  char c;
  for (int i = 0; i < q; i++) {
    scanf("\n%c %I64d", &c, &a);
    if (c == '+') {
      insert(a);
    } else if (c == '-')
      del(a);
    else
      printf("%I64d\n", query(a));
  }
  return 0;
}

### Prompt

Please formulate 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 Trie[7000001][2], sz = 0, A[7000001];
void insert(long long int a) {
  int cur = 0;
  A[cur]++;
  for (int i = 31; i >= 0; i--) {
    int d = (a & (1ll << i)) ? 1 : 0;
    if (Trie[cur][d] == 0) {
      Trie[cur][d] = ++sz;
    }
    cur = Trie[cur][d];
    A[cur]++;
  }
}
void del(long long int a) {
  int cur = 0;
  for (int i = 31; i >= 0; i--) {
    int d = (a & (1ll << i)) ? 1 : 0;
    A[cur]--;
    cur = Trie[cur][d];
  }
  A[cur]--;
}
long long int query(long long int a) {
  long long int ans = 0;
  int cur = 0;
  if (A[cur] == 0) return a;
  for (int i = 31; i >= 0; i--) {
    int d = (a & (1ll << i)) ? 1 : 0;
    d = 1 - d;
    if (Trie[cur][d] != 0 && (A[Trie[cur][d]] != 0)) {
      cur = Trie[cur][d];
      ans = ans | (1ll << i);
    } else {
      cur = Trie[cur][1 - d];
    }
  }
  return max(a, ans);
}
int main() {
  long long int q;
  cin >> q;
  long long int a;
  char c;
  for (int i = 0; i < q; i++) {
    scanf("\n%c %I64d", &c, &a);
    if (c == '+') {
      insert(a);
    } else if (c == '-')
      del(a);
    else
      printf("%I64d\n", query(a));
  }
  return 0;
}

```