#include<iostream>
#include<cmath>
#include<algorithm>
using namespace std;
int a[24][24],p[16],b[24],n,k,pp[24],kk[24];
void Read()
{
    int i,j;
    cin>>n>>k;
    for(i=1;i<=n;i++)
    {
        cin>>p[i];
        for(j=1;j<=p[i];j++)
        cin>>a[i][j];
    }
}
void Solve()
{
    int i,j,br=0,bb=0,brr=0;
    for(i=1;i<=n;i++)
    {
        for(j=1;j<=k;j++)
        {
            if(a[i][j])bb++;
        }
        for(j=1;j<=k;j++)
        if(a[i][j])
        {
            if(b[a[i][j]]>=1)
            {
                if(pp[b[a[i][j]]]<bb)brr++;
                else brr=-1;
                pp[b[a[i][j]]]=bb;
            }
            else
            {
                b[a[i][j]]++;
                pp[b[a[i][j]]]=bb;
            }
        }
        else break;
        if(brr==(-1))
        {
            kk[i]=-1;
        }
        if(brr>0)
        kk[pp[b[a[i][j]]]]=-1;
        bb=0;
    }
    for(i=1;i<=n;i++)
    if(kk[i]!=(-1))br++;
    cout<<br<<endl;
    for(i=1;i<=n;i++)
    if(kk[i]!=(-1))cout<<i<<' ';
}
int main()
{
    Read();
    Solve();
    return 0;
}