#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<long, long>;
using vi = vector<int>;
using vl = vector<long long>;
void fastIO() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
}
const ll mod = 1e9 + 7;
void solve() {
  int q;
  cin >> q;
  map<ll, int> mp;
  set<ll> second;
  second.insert(0);
  while (q--) {
    char c;
    ll x;
    cin >> c >> x;
    if (c == '+') {
      mp[x]++;
      if (mp[x] == 1) {
        second.insert(x);
      }
    } else if (c == '-') {
      mp[x]--;
      if (mp[x] == 0) {
        second.erase(x);
      }
    } else {
      ll l = 0, r = (1LL << 32) - 1;
      for (ll i = 31; i >= 0; i--) {
        if ((1LL << i) & x) {
          r -= (1LL << i);
        } else {
          l += (1LL << i);
        }
        auto j = second.lower_bound(l);
        auto k = second.upper_bound(r);
        if (k == j) {
          if ((1LL << i) & x) {
            l += (1LL << i);
            r += (1LL << i);
          } else {
            l -= (1LL << i);
            r -= (1LL << i);
          }
        }
      }
      cout << (x ^ *second.lower_bound(l)) << endl;
    }
  }
}
int main() {
  fastIO();
  cout << setprecision(15) << fixed;
  int t = 1;
  while (t--) solve();
  return 0;
}

### Prompt

Construct a Cpp code solution to the problem outlined:

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;
using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<long, long>;
using vi = vector<int>;
using vl = vector<long long>;
void fastIO() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
}
const ll mod = 1e9 + 7;
void solve() {
  int q;
  cin >> q;
  map<ll, int> mp;
  set<ll> second;
  second.insert(0);
  while (q--) {
    char c;
    ll x;
    cin >> c >> x;
    if (c == '+') {
      mp[x]++;
      if (mp[x] == 1) {
        second.insert(x);
      }
    } else if (c == '-') {
      mp[x]--;
      if (mp[x] == 0) {
        second.erase(x);
      }
    } else {
      ll l = 0, r = (1LL << 32) - 1;
      for (ll i = 31; i >= 0; i--) {
        if ((1LL << i) & x) {
          r -= (1LL << i);
        } else {
          l += (1LL << i);
        }
        auto j = second.lower_bound(l);
        auto k = second.upper_bound(r);
        if (k == j) {
          if ((1LL << i) & x) {
            l += (1LL << i);
            r += (1LL << i);
          } else {
            l -= (1LL << i);
            r -= (1LL << i);
          }
        }
      }
      cout << (x ^ *second.lower_bound(l)) << endl;
    }
  }
}
int main() {
  fastIO();
  cout << setprecision(15) << fixed;
  int t = 1;
  while (t--) solve();
  return 0;
}

```