#include <bits/stdc++.h>
using namespace std;
int q, x;
char c;
struct trie {
  int cunt;
  trie *one, *zer;
  trie() {
    cunt = 0;
    one = zer = 0;
  }
};
int get_count(trie *t) {
  if (t == 0) return 0;
  return t->cunt;
}
void add(trie *t, int num, int bit, int test) {
  t->cunt += test;
  if (bit == -1) return;
  if (num & (1 << bit)) {
    if (get_count(t->one) == 0) t->one = new trie();
    add(t->one, num, bit - 1, test);
  } else {
    if (get_count(t->zer) == 0) t->zer = new trie();
    add(t->zer, num, bit - 1, test);
  }
}
int sol(trie *t, int num, int bit) {
  if (bit == -1) return 0;
  if (num & (1 << bit)) {
    if (get_count(t->zer) != 0) return (1 << bit) + sol(t->zer, num, bit - 1);
    return sol(t->one, num, bit - 1);
  } else {
    if (get_count(t->one) != 0) return (1 << bit) + sol(t->one, num, bit - 1);
    return sol(t->zer, num, bit - 1);
  }
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  trie *t = new trie();
  add(t, 0, 31, 1);
  cin >> q;
  while (q--) {
    cin >> c >> x;
    if (c == '+') add(t, x, 31, 1);
    if (c == '-') add(t, x, 31, -1);
    if (c == '?') cout << sol(t, x, 31) << endl;
  }
  return 0;
}

### 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;
int q, x;
char c;
struct trie {
  int cunt;
  trie *one, *zer;
  trie() {
    cunt = 0;
    one = zer = 0;
  }
};
int get_count(trie *t) {
  if (t == 0) return 0;
  return t->cunt;
}
void add(trie *t, int num, int bit, int test) {
  t->cunt += test;
  if (bit == -1) return;
  if (num & (1 << bit)) {
    if (get_count(t->one) == 0) t->one = new trie();
    add(t->one, num, bit - 1, test);
  } else {
    if (get_count(t->zer) == 0) t->zer = new trie();
    add(t->zer, num, bit - 1, test);
  }
}
int sol(trie *t, int num, int bit) {
  if (bit == -1) return 0;
  if (num & (1 << bit)) {
    if (get_count(t->zer) != 0) return (1 << bit) + sol(t->zer, num, bit - 1);
    return sol(t->one, num, bit - 1);
  } else {
    if (get_count(t->one) != 0) return (1 << bit) + sol(t->one, num, bit - 1);
    return sol(t->zer, num, bit - 1);
  }
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  trie *t = new trie();
  add(t, 0, 31, 1);
  cin >> q;
  while (q--) {
    cin >> c >> x;
    if (c == '+') add(t, x, 31, 1);
    if (c == '-') add(t, x, 31, -1);
    if (c == '?') cout << sol(t, x, 31) << endl;
  }
  return 0;
}

```