func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int t;     cin >> t;     while (t-- > 0) {       int n;       cin >> n;       vector<vector<int>> a;       int b[n + 1];       for (int i = 0; i <= n; i++) b[i] = 0;       int count = 0;       int s = 0;       for (int i = 0; i < n; i++) {         vector<int> x;         int k;         cin >> k;         int c = 0;         for (int j = 0; j < k; j++) {           int q;           cin >> q;           x.push_back(q);           if (c == 0) {             if (b[q] == 0) {               b[q]++;               count++;               c = 1;             }           }         }         if (c == 0) s = i;         a.push_back(x);       }       if (count == n) {         cout <<  OPTIMAL  << endl;       } else {         s++;         int f = 0;         for (int i = 0; i < n; i++) {           if (b[i + 1] == 0) {             f = i;           }         }         f++;         cout <<  IMPROVE  << endl;         cout << s <<     << f << endl;       }     }     return 0;   }   