func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios::sync_with_stdio(false);     cin.tie(NULL);     multiset<int> s;     s.insert(0);     int q;     cin >> q;     while (q--) {       char c;       int x;       cin >> c >> x;       if (c ==  + ) {         s.insert(x);       } else if (c ==  - ) {         s.erase(s.find(x));       } else {         int cur = 0;         for (int i = 30; i >= 0; i--) {           if (((1 << i) & x) == 0) {             cur |= (1 << i);             auto it = s.lower_bound(cur);             if (it == s.end() || (cur >> i) != (*it >> i)) cur ^= (1 << i);           } else {             auto it = s.lower_bound(cur);             if (it == s.end() || (cur >> i) != (*it >> i)) cur |= (1 << i);           }         }         cout << (x ^ cur) <<   n ;       }     }     return 0;   }   