#include <bits/stdc++.h>
using namespace std;
const int MOD = 1000000007;
const long long INF = 1e18;
const long double PI = 4 * atan((long double)1);
class Trie {
 public:
  class TrieNode {
   public:
    TrieNode *next[2];
    int count;
    TrieNode() {
      next[0] = next[1] = nullptr;
      count = 0;
    }
    TrieNode(bool e) {
      next[0] = next[1] = nullptr;
      count = 0;
    }
  };
  TrieNode *root;
  Trie() { root = new TrieNode(); }
  void remove(int v) {
    string second = "";
    for (int i = 31; i >= 0; i--) {
      if (v & (1 << i)) {
        second += "1";
      } else {
        second += "0";
      }
    }
    auto curr = root;
    for (int i = 0; i < (int)second.size(); i++) {
      if (!curr->next[second[i] - '0']) {
        break;
      }
      curr = curr->next[second[i] - '0'];
      curr->count--;
    }
  }
  void insert(int v) {
    string second = "";
    for (int i = 31; i >= 0; i--) {
      if (v & (1 << i)) {
        second += "1";
      } else {
        second += "0";
      }
    }
    TrieNode *curr = root;
    for (int i = 0; i < (int)second.size(); i++) {
      if (!curr->next[second[i] - '0']) {
        curr->next[second[i] - '0'] = new TrieNode();
      }
      curr = curr->next[second[i] - '0'];
      curr->count++;
    }
  }
  unsigned long long query(int v) {
    string second = "";
    for (int i = 31; i >= 0; i--) {
      if (v & (1 << i)) {
        second += "1";
      } else {
        second += "0";
      }
    }
    auto trav = root;
    unsigned long long ans = 0;
    for (int i = 0; i < (int)second.size(); i++) {
      char comp = (second[i] == '1') ? '0' : '1';
      int lookingfor = comp - '0';
      if (trav->next[lookingfor] && trav->next[lookingfor]->count > 0) {
        trav = trav->next[lookingfor];
        ans += (1 << (31 - i));
      } else {
        trav = trav->next[1 - lookingfor];
      }
    }
    return ans;
  }
};
long long q;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  Trie t;
  t.insert(0);
  cin >> q;
  for (int i = 0; i < (q); i++) {
    char query;
    long long num;
    cin >> query >> num;
    if (query == '+') {
      t.insert(num);
    } else if (query == '-') {
      t.remove(num);
    } else {
      cout << t.query(num) << endl;
    }
  }
}

### 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;
const int MOD = 1000000007;
const long long INF = 1e18;
const long double PI = 4 * atan((long double)1);
class Trie {
 public:
  class TrieNode {
   public:
    TrieNode *next[2];
    int count;
    TrieNode() {
      next[0] = next[1] = nullptr;
      count = 0;
    }
    TrieNode(bool e) {
      next[0] = next[1] = nullptr;
      count = 0;
    }
  };
  TrieNode *root;
  Trie() { root = new TrieNode(); }
  void remove(int v) {
    string second = "";
    for (int i = 31; i >= 0; i--) {
      if (v & (1 << i)) {
        second += "1";
      } else {
        second += "0";
      }
    }
    auto curr = root;
    for (int i = 0; i < (int)second.size(); i++) {
      if (!curr->next[second[i] - '0']) {
        break;
      }
      curr = curr->next[second[i] - '0'];
      curr->count--;
    }
  }
  void insert(int v) {
    string second = "";
    for (int i = 31; i >= 0; i--) {
      if (v & (1 << i)) {
        second += "1";
      } else {
        second += "0";
      }
    }
    TrieNode *curr = root;
    for (int i = 0; i < (int)second.size(); i++) {
      if (!curr->next[second[i] - '0']) {
        curr->next[second[i] - '0'] = new TrieNode();
      }
      curr = curr->next[second[i] - '0'];
      curr->count++;
    }
  }
  unsigned long long query(int v) {
    string second = "";
    for (int i = 31; i >= 0; i--) {
      if (v & (1 << i)) {
        second += "1";
      } else {
        second += "0";
      }
    }
    auto trav = root;
    unsigned long long ans = 0;
    for (int i = 0; i < (int)second.size(); i++) {
      char comp = (second[i] == '1') ? '0' : '1';
      int lookingfor = comp - '0';
      if (trav->next[lookingfor] && trav->next[lookingfor]->count > 0) {
        trav = trav->next[lookingfor];
        ans += (1 << (31 - i));
      } else {
        trav = trav->next[1 - lookingfor];
      }
    }
    return ans;
  }
};
long long q;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  Trie t;
  t.insert(0);
  cin >> q;
  for (int i = 0; i < (q); i++) {
    char query;
    long long num;
    cin >> query >> num;
    if (query == '+') {
      t.insert(num);
    } else if (query == '-') {
      t.remove(num);
    } else {
      cout << t.query(num) << endl;
    }
  }
}

```