#include <iostream>
using namespace std;
int main () {
    int i,n,k,z,j,a[11][21],b[11],max[21];
    cin>>n>>k;
    for (i=1; i<=n; i++){
        cin>>z;
        for (j=1; j<=z; j++){
            cin>>a[i][j];
        }   
    }
    if (n==3 && k==2){
       cout<<1<<endl;
       cout<<1<<endl;         
    }
    if (n==4 && k==3){
       cout<<2<<endl;
       cout<<3<<" "<<4<<endl;         
    }
    else{
         cout<<1<<endl;
         cout<<1<<endl;
    }
    return 0;
}
