#include <bits/stdc++.h>
using namespace std;
int dr[] = {0, 1, -1, 0, 1, -1, -1, 1};
int dc[] = {-1, 0, 0, 1, 1, 1, -1, -1};
const int N = 33 * 2 * (1e5);
long long int cnt = 1LL;
long long int qtd[N];
long long int trie[N][2];
void add(long long int n) {
  long long int no = 0;
  qtd[no]++;
  bitset<33> s(n);
  for (long long int i = 33; i >= 0; i--) {
    long long int c = s[i];
    if (!trie[no][c]) {
      trie[no][c] = cnt++;
    }
    no = trie[no][c];
    qtd[no]++;
  }
}
void remove(long long int n) {
  long long int no = 0;
  qtd[no]--;
  bitset<33> s(n);
  for (long long int i = 33; i >= 0; i--) {
    long long int c = s[i];
    no = trie[no][c];
    qtd[no]--;
  }
}
long long int query(long long int n) {
  long long int no = 0;
  bitset<33> s(n);
  for (long long int i = 33; i >= 0; i--) {
    long long int c = s[i];
    long long int oposto = c ^ 1;
    if (trie[no][oposto] && qtd[trie[no][oposto]]) {
      s[i] = 1;
      no = trie[no][oposto];
    } else {
      s[i] = 0;
      no = trie[no][c];
    }
  }
  return (long long int)s.to_ulong();
}
int main() {
  memset(trie, 0, sizeof trie);
  memset(qtd, 0, sizeof qtd);
  long long int n;
  cin >> n;
  char c;
  long long int x;
  add(0LL);
  while (n--) {
    cin >> c >> x;
    if (c == '+')
      add(x);
    else if (c == '-') {
      remove(x);
    } else
      cout << query(x) << "\n";
  }
  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 dr[] = {0, 1, -1, 0, 1, -1, -1, 1};
int dc[] = {-1, 0, 0, 1, 1, 1, -1, -1};
const int N = 33 * 2 * (1e5);
long long int cnt = 1LL;
long long int qtd[N];
long long int trie[N][2];
void add(long long int n) {
  long long int no = 0;
  qtd[no]++;
  bitset<33> s(n);
  for (long long int i = 33; i >= 0; i--) {
    long long int c = s[i];
    if (!trie[no][c]) {
      trie[no][c] = cnt++;
    }
    no = trie[no][c];
    qtd[no]++;
  }
}
void remove(long long int n) {
  long long int no = 0;
  qtd[no]--;
  bitset<33> s(n);
  for (long long int i = 33; i >= 0; i--) {
    long long int c = s[i];
    no = trie[no][c];
    qtd[no]--;
  }
}
long long int query(long long int n) {
  long long int no = 0;
  bitset<33> s(n);
  for (long long int i = 33; i >= 0; i--) {
    long long int c = s[i];
    long long int oposto = c ^ 1;
    if (trie[no][oposto] && qtd[trie[no][oposto]]) {
      s[i] = 1;
      no = trie[no][oposto];
    } else {
      s[i] = 0;
      no = trie[no][c];
    }
  }
  return (long long int)s.to_ulong();
}
int main() {
  memset(trie, 0, sizeof trie);
  memset(qtd, 0, sizeof qtd);
  long long int n;
  cin >> n;
  char c;
  long long int x;
  add(0LL);
  while (n--) {
    cin >> c >> x;
    if (c == '+')
      add(x);
    else if (c == '-') {
      remove(x);
    } else
      cout << query(x) << "\n";
  }
  return 0;
}

```