func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     int n, m;     cin >> n >> m;     map<int, set<pair<int, string>, greater<pair<int, string> > > > mp;     for (int i = 0; i < n; i++) {       string s;       int a, b;       cin >> s >> a >> b;       mp[a].insert(pair<int, string>(b, s));     }     for (int i = 1; i <= m; i++) {       pair<int, string> a, b, c;       auto it = mp[i].begin();       a = *it;       it++;       b = *it;       if (mp[i].size() > 2)         it++;       else {         cout << a.second <<     << b.second << endl;         continue;       }       c = *it;       if ((b.first == c.first)) {         cout <<  ?  << endl;       } else {         cout << a.second <<     << b.second << endl;       }     }     return 0;   }   