func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 1e5 + 5;   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     int t;     cin >> t;     while (t--) {       int n, count = 1, ans = 0, a, b, freq[N] = {0}, pf, v;       cin >> n;       for (int i = 0; i < n; i++) {         cin >> a;         v = 0;         for (int j = 0; j < a; j++) {           cin >> b;           if (j < count && !v) {             if (!freq[b]) {               v = 1;               freq[b]++;             }           }         }         if (!v) {           pf = i + 1;         }         count++;       }       v = 0;       for (int i = 1; i <= n; i++) {         if (!freq[i]) {           v = i;           break;         }       }       if (v) {         cout <<  IMPROVE n  << pf <<     << v <<   n ;       } else {         cout <<  OPTIMAL n ;       }     }   }   