#include <bits/stdc++.h>
using namespace std;
void read(long long a = 0) {
  freopen("in", "r", stdin);
  if (a) freopen("out", "w", stdout);
}
struct trie {
  long long num;
  trie* node[2];
  trie() {
    num = 0;
    node[0] = node[1] = 0;
  }
  void insert(long long* a, long long type) {
    num += 1 - 2 * (type == -1);
    if (*a == -1) return;
    if (node[*a] == 0) node[*a] = new trie;
    node[*a]->insert(a + 1, type);
  }
  long long get(long long* a, long long i) {
    if (a[i] == -1) return 0;
    if (node[!a[i]] && node[!a[i]]->num)
      return (1 << (30 - i)) + node[!a[i]]->get(a, i + 1);
    else
      return node[a[i]]->get(a, i + 1);
  }
};
int main() {
  ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  trie* tree = new trie();
  long long a[32] = {};
  a[31] = -1;
  tree->insert(a, 1);
  long long q;
  cin >> q;
  while (q--) {
    char tmp;
    cin >> tmp;
    if (tmp == '?') {
      long long x;
      cin >> x;
      for (int i = 0; i < 31; i++) a[i] = (x & (1 << (31 - i - 1)) ? 1 : 0);
      cout << tree->get(a, 0);
      cout << "\n";
    } else {
      long long type = (tmp == '+' ? 1 : -1);
      long long x;
      cin >> x;
      for (int i = 0; i < 31; i++) a[i] = (x & (1 << (31 - i - 1)) ? 1 : 0);
      tree->insert(a, type);
    }
  }
}

### Prompt

Please create a solution in CPP 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;
void read(long long a = 0) {
  freopen("in", "r", stdin);
  if (a) freopen("out", "w", stdout);
}
struct trie {
  long long num;
  trie* node[2];
  trie() {
    num = 0;
    node[0] = node[1] = 0;
  }
  void insert(long long* a, long long type) {
    num += 1 - 2 * (type == -1);
    if (*a == -1) return;
    if (node[*a] == 0) node[*a] = new trie;
    node[*a]->insert(a + 1, type);
  }
  long long get(long long* a, long long i) {
    if (a[i] == -1) return 0;
    if (node[!a[i]] && node[!a[i]]->num)
      return (1 << (30 - i)) + node[!a[i]]->get(a, i + 1);
    else
      return node[a[i]]->get(a, i + 1);
  }
};
int main() {
  ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  trie* tree = new trie();
  long long a[32] = {};
  a[31] = -1;
  tree->insert(a, 1);
  long long q;
  cin >> q;
  while (q--) {
    char tmp;
    cin >> tmp;
    if (tmp == '?') {
      long long x;
      cin >> x;
      for (int i = 0; i < 31; i++) a[i] = (x & (1 << (31 - i - 1)) ? 1 : 0);
      cout << tree->get(a, 0);
      cout << "\n";
    } else {
      long long type = (tmp == '+' ? 1 : -1);
      long long x;
      cin >> x;
      for (int i = 0; i < 31; i++) a[i] = (x & (1 << (31 - i - 1)) ? 1 : 0);
      tree->insert(a, type);
    }
  }
}

```