func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long int mod = 998244353;   const int sz = 1e5 + 3, inf = 1e9 + 10;   int a[sz], match[sz], c[sz];   int fr[sz];   bool vis[sz];   long long int x[sz];   void solve() {     memset(vis, 1, sizeof vis);     memset(match, 0, sizeof match);     int n;     cin >> n;     for (int i = 1; i <= n; i++) {       int k;       cin >> k;       for (int j = 0; j < k; j++) cin >> a[j];       for (int j = 0; j < k; j++) {         if (vis[a[j]]) {           vis[a[j]] = 0;           match[i] = a[j];           break;         }       }     }     bool f = 0;     for (int i = 1; i <= n; i++) {       if (match[i]) continue;       for (int j = 1; j <= n; j++) {         if (vis[j]) {           cout <<  IMPROVE n ;           cout << i <<     << j <<   n ;           f = 1;           break;         }       }       if (f) break;     }     if (!f) cout <<  OPTIMAL n ;   }   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     int t;     cin >> t;     while (t--) solve();     return 0;   }   