#include <bits/stdc++.h>
using namespace std;
struct trie {
  trie* child[2];
  int NOB = 0;
};
trie* getnode() {
  trie* got = new trie;
  got->child[0] = NULL;
  got->child[1] = NULL;
  return got;
}
void insert(trie*& root, unsigned long int x) {
  trie* copy = root;
  for (int mask = 31; mask >= 0; --mask) {
    ++copy->NOB;
    bool bit = (x & (1 << mask));
    if (!copy->child[bit]) copy->child[bit] = getnode();
    copy = copy->child[bit];
  }
  ++copy->NOB;
}
void ers(trie*& root, unsigned long int x) {
  trie* copy = root;
  for (int mask = 31; mask >= 0; --mask) {
    --copy->NOB;
    bool bit = (x & (1 << mask));
    copy = copy->child[bit];
  }
  --copy->NOB;
}
unsigned long int ZOR(trie* root, unsigned long int x) {
  trie* copy = root;
  unsigned long int xorr = 0;
  for (int mask = 31; mask >= 0; --mask) {
    unsigned long int bit = (x & (1 << mask));
    if (copy->child[bool(!bit)] && copy->child[bool(!bit)]->NOB) {
      xorr |= (1 << mask);
      copy = copy->child[bool(!bit)];
    } else
      copy = copy->child[bool(bit)];
  }
  return xorr;
}
int main() {
  ios_base::sync_with_stdio(false);
  cout.tie(NULL);
  cin.tie(NULL);
  trie* S = getnode();
  insert(S, 0);
  unsigned long int x;
  int n;
  char c;
  cin >> n;
  for (int t = 0; t < n; ++t) {
    cin >> c >> x;
    switch (c) {
      case '+':
        insert(S, x);
        break;
      case '-':
        ers(S, x);
        break;
      case '?':
        unsigned long int xorr = ZOR(S, x);
        cout << xorr << '\n';
        break;
    }
  }
}

### Prompt

Your challenge is to write 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;
struct trie {
  trie* child[2];
  int NOB = 0;
};
trie* getnode() {
  trie* got = new trie;
  got->child[0] = NULL;
  got->child[1] = NULL;
  return got;
}
void insert(trie*& root, unsigned long int x) {
  trie* copy = root;
  for (int mask = 31; mask >= 0; --mask) {
    ++copy->NOB;
    bool bit = (x & (1 << mask));
    if (!copy->child[bit]) copy->child[bit] = getnode();
    copy = copy->child[bit];
  }
  ++copy->NOB;
}
void ers(trie*& root, unsigned long int x) {
  trie* copy = root;
  for (int mask = 31; mask >= 0; --mask) {
    --copy->NOB;
    bool bit = (x & (1 << mask));
    copy = copy->child[bit];
  }
  --copy->NOB;
}
unsigned long int ZOR(trie* root, unsigned long int x) {
  trie* copy = root;
  unsigned long int xorr = 0;
  for (int mask = 31; mask >= 0; --mask) {
    unsigned long int bit = (x & (1 << mask));
    if (copy->child[bool(!bit)] && copy->child[bool(!bit)]->NOB) {
      xorr |= (1 << mask);
      copy = copy->child[bool(!bit)];
    } else
      copy = copy->child[bool(bit)];
  }
  return xorr;
}
int main() {
  ios_base::sync_with_stdio(false);
  cout.tie(NULL);
  cin.tie(NULL);
  trie* S = getnode();
  insert(S, 0);
  unsigned long int x;
  int n;
  char c;
  cin >> n;
  for (int t = 0; t < n; ++t) {
    cin >> c >> x;
    switch (c) {
      case '+':
        insert(S, x);
        break;
      case '-':
        ers(S, x);
        break;
      case '?':
        unsigned long int xorr = ZOR(S, x);
        cout << xorr << '\n';
        break;
    }
  }
}

```