#include <bits/stdc++.h>
using namespace std;
struct TrieNode {
  TrieNode() : freq(0) { child[0] = child[1] = nullptr; }
  TrieNode* child[2];
  int freq;
} * root;
deque<TrieNode> trie;
TrieNode* fetchNode() {
  trie.push_back(TrieNode());
  return &trie.back();
}
void upd(int x, int val) {
  TrieNode* cur = root;
  for (int i = 30; i >= 0; --i) {
    int bit = ((x >> i) & 1);
    if (cur->child[bit] == nullptr) {
      cur->child[bit] = fetchNode();
    }
    cur = cur->child[bit];
    cur->freq += val;
  }
}
int qwr(int x) {
  TrieNode* cur = root;
  int ret = 0;
  for (int i = 30; i >= 0; --i) {
    int bit = ((x >> i) & 1);
    if (cur->child[!bit] != nullptr && cur->child[!bit]->freq) {
      ret |= (1 << i);
      cur = cur->child[!bit];
    } else {
      cur = cur->child[bit];
    }
  }
  return ret;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  root = fetchNode();
  upd(0, 1);
  int q;
  cin >> q;
  while (q--) {
    char op;
    int x;
    cin >> op >> x;
    if (op == '+')
      upd(x, +1);
    else if (op == '-')
      upd(x, -1);
    else
      cout << qwr(x) << "\n";
  }
  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 TrieNode {
  TrieNode() : freq(0) { child[0] = child[1] = nullptr; }
  TrieNode* child[2];
  int freq;
} * root;
deque<TrieNode> trie;
TrieNode* fetchNode() {
  trie.push_back(TrieNode());
  return &trie.back();
}
void upd(int x, int val) {
  TrieNode* cur = root;
  for (int i = 30; i >= 0; --i) {
    int bit = ((x >> i) & 1);
    if (cur->child[bit] == nullptr) {
      cur->child[bit] = fetchNode();
    }
    cur = cur->child[bit];
    cur->freq += val;
  }
}
int qwr(int x) {
  TrieNode* cur = root;
  int ret = 0;
  for (int i = 30; i >= 0; --i) {
    int bit = ((x >> i) & 1);
    if (cur->child[!bit] != nullptr && cur->child[!bit]->freq) {
      ret |= (1 << i);
      cur = cur->child[!bit];
    } else {
      cur = cur->child[bit];
    }
  }
  return ret;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  root = fetchNode();
  upd(0, 1);
  int q;
  cin >> q;
  while (q--) {
    char op;
    int x;
    cin >> op >> x;
    if (op == '+')
      upd(x, +1);
    else if (op == '-')
      upd(x, -1);
    else
      cout << qwr(x) << "\n";
  }
  return 0;
}

```