#include <fstream>
#include <algorithm>

using namespace std;
ifstream fin("interclasari.in");
ofstream fout("interclasari.out");

int k,v[21],n[1000001],aux[21000001];
long long nr;
int main()
{
    fin>>k;
    for(int i=1;i<=k;i++)
    {
        fin>>v[i];
        for(int j=1;j<=v[i];j++)
        {
            fin>>n[j];
            aux[++nr]=n[j];
        }
    }
    sort(aux+1,aux+nr+1);
    fout<<nr<<"\n";
    for(int i=1;i<=nr;i++)
    {
        fout<<aux[i]<<" ";
    }
    return 0;
}