#include <iostream>
using namespace std;
int main ()
{
    int n,k,a,p,j;
    cin>>n>>k;
    for(int i=1;i<=n;i++) {cin>>a;
                           for(p=1;p<=a;p++) cin>>j;}
    if(n==3) cout<<1<<endl<<1<<endl;
    if(n==4) cout<<3<<endl<<3<<' '<<4<<endl;
    if(n!=3 && n!=4) cout<<1<<endl<<1<<endl;
    return 0;
}
