#include <bits/stdc++.h>
using namespace std;
typedef struct data {
  data* bit[2];
  long long cnt = 0;
} trie;
trie* head;
void insert(long long x) {
  trie* node = head;
  for (long long i = 30; i >= 0; i--) {
    long long curbit = (x >> i) & 1;
    if (node->bit[curbit] == NULL) {
      node->bit[curbit] = new trie();
    }
    node = node->bit[curbit];
    node->cnt++;
  }
}
void remove(long long x) {
  trie* node = head;
  for (long long i = 30; i >= 0; i--) {
    long long curbit = (x >> i) & 1;
    node = node->bit[curbit];
    node->cnt--;
  }
}
long long maxxor(long long x) {
  trie* node = head;
  long long ans = 0;
  for (long long i = 30; i >= 0; i--) {
    long long curbit = (x >> i) & 1;
    if (node->bit[curbit ^ 1] != NULL && node->bit[curbit ^ 1]->cnt > 0) {
      ans += (1LL << i);
      node = node->bit[curbit ^ 1];
    } else
      node = node->bit[curbit];
  }
  return ans;
}
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  head = new trie();
  insert(0);
  long long q;
  cin >> q;
  while (q--) {
    char ch;
    cin >> ch;
    long long x;
    cin >> x;
    if (ch == '+')
      insert(x);
    else if (ch == '-')
      remove(x);
    else
      cout << maxxor(x) << "\n";
  }
  return 0;
}

### Prompt

Generate 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;
typedef struct data {
  data* bit[2];
  long long cnt = 0;
} trie;
trie* head;
void insert(long long x) {
  trie* node = head;
  for (long long i = 30; i >= 0; i--) {
    long long curbit = (x >> i) & 1;
    if (node->bit[curbit] == NULL) {
      node->bit[curbit] = new trie();
    }
    node = node->bit[curbit];
    node->cnt++;
  }
}
void remove(long long x) {
  trie* node = head;
  for (long long i = 30; i >= 0; i--) {
    long long curbit = (x >> i) & 1;
    node = node->bit[curbit];
    node->cnt--;
  }
}
long long maxxor(long long x) {
  trie* node = head;
  long long ans = 0;
  for (long long i = 30; i >= 0; i--) {
    long long curbit = (x >> i) & 1;
    if (node->bit[curbit ^ 1] != NULL && node->bit[curbit ^ 1]->cnt > 0) {
      ans += (1LL << i);
      node = node->bit[curbit ^ 1];
    } else
      node = node->bit[curbit];
  }
  return ans;
}
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  head = new trie();
  insert(0);
  long long q;
  cin >> q;
  while (q--) {
    char ch;
    cin >> ch;
    long long x;
    cin >> x;
    if (ch == '+')
      insert(x);
    else if (ch == '-')
      remove(x);
    else
      cout << maxxor(x) << "\n";
  }
  return 0;
}

```