#include <bits/stdc++.h>
using namespace std;
struct node {
  int count = 0;
  node *next[2];
  node() {
    this->next[1] = NULL;
    this->next[0] = NULL;
  }
};
void insert(int x, node *head) {
  for (int i = 30; i >= 0; i--) {
    int bit = ((x >> i) & 1);
    if (head->next[bit] == NULL) {
      head->next[bit] = new node();
    }
    head = head->next[bit];
    head->count++;
  }
}
void remove(int x, node *head) {
  for (int i = 30; i >= 0; i--) {
    int bit = ((x >> i) & 1);
    head = head->next[bit];
    head->count--;
  }
}
long long maxXor(int x, node *head) {
  long long ans = 0;
  for (int i = 30; i >= 0; i--) {
    int bit = ((x >> i) & 1);
    if ((head->next[1 ^ bit] != NULL) && (head->next[1 ^ bit])->count > 0) {
      head = head->next[1 - bit];
      ans = (ans | (1 << i));
    } else {
      head = head->next[bit];
    }
  }
  return ans;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  node *trie = new node();
  insert(0, trie);
  int n, v;
  cin >> n;
  char c;
  while (n--) {
    cin >> c >> v;
    if (c == '+') {
      insert(v, trie);
    } else if (c == '-') {
      remove(v, trie);
    } else {
      cout << maxXor(v, trie) << endl;
    }
  }
  return 0;
}

### Prompt

Develop a solution in cpp to the problem described below:

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;
struct node {
  int count = 0;
  node *next[2];
  node() {
    this->next[1] = NULL;
    this->next[0] = NULL;
  }
};
void insert(int x, node *head) {
  for (int i = 30; i >= 0; i--) {
    int bit = ((x >> i) & 1);
    if (head->next[bit] == NULL) {
      head->next[bit] = new node();
    }
    head = head->next[bit];
    head->count++;
  }
}
void remove(int x, node *head) {
  for (int i = 30; i >= 0; i--) {
    int bit = ((x >> i) & 1);
    head = head->next[bit];
    head->count--;
  }
}
long long maxXor(int x, node *head) {
  long long ans = 0;
  for (int i = 30; i >= 0; i--) {
    int bit = ((x >> i) & 1);
    if ((head->next[1 ^ bit] != NULL) && (head->next[1 ^ bit])->count > 0) {
      head = head->next[1 - bit];
      ans = (ans | (1 << i));
    } else {
      head = head->next[bit];
    }
  }
  return ans;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  node *trie = new node();
  insert(0, trie);
  int n, v;
  cin >> n;
  char c;
  while (n--) {
    cin >> c >> v;
    if (c == '+') {
      insert(v, trie);
    } else if (c == '-') {
      remove(v, trie);
    } else {
      cout << maxXor(v, trie) << endl;
    }
  }
  return 0;
}

```