#include <fstream>
#include <algorithm>
using namespace std;
ifstream fin ("interclasari.in");
ofstream fout ("interclasari.out");
long long k,p,n,m,i,j,v[2500001];
int main()
{
    fin>>k;
    p=1;
    for (i=1; i<=k; i++)
    {
        fin>>m;
        n=n+m;
        for (j=1; j<=m; j++)
        {
            fin>>v[p];
            p++;
        }
    }
    fout<<n<<"\n";
    sort (v+1,v+n+1);
    fout<<v[1]<<" ";
    for (i=2; i<=n; i++)
    {
        if (v[i]!=v[i-1])
            fout<<v[i]<<" ";
    }
    return 0;
}