func_code_string: #include <bits/stdc++.h>   using namespace std;   int32_t main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     int t;     cin >> t;     while (t--) {       int n;       cin >> n;       int n1 = n;       int k1;       int k[n + 1];       int pri[n + 1];       for (int i = 1; i <= n; i++) {         k[i] = 0;         pri[i] = 0;       }       int f = 0;       std::vector<int> nhi;       for (int j = 1; j <= n; j++) {         f = 0;         cin >> k1;         int pr[k1 + 1];         for (int i = 1; i <= k1; i++) {           cin >> pr[i];         }         for (int i = 1; i <= k1; i++) {           if (k[pr[i]] == 0) {             k[pr[i]] = 1;             pri[j] = 1;             break;           }         }         if (pri[j] == 0) {           nhi.push_back(j);         }       }       if (nhi.empty())         cout <<  OPTIMAL               <<   n ;       else {         int g;         for (int i = 1; i <= n; i++) {           if (k[i] == 0) {             g = i;             break;           }         }         cout <<  IMPROVE               <<   n ;         cout << nhi[0] <<     << g <<   n ;       }     }     return 0;   }   