#include <fstream>

using namespace std;

unsigned short int K;
unsigned int Ni;
unsigned int photos[1000001];

unsigned int temp;
unsigned int i, j;

unsigned int X;
unsigned int sol[20000001];

int main ()
{
    ifstream fin ("interclasari.in");
    fin >> K;
    for (i=1; i<=K; i++)
    {
        fin >> Ni;
        for (j=1; j<=Ni; j++)
        {
            fin >> photos[j];
            X++;
            sol[X] = photos[j];
        }
    }
    fin.close();
    for (i=1; i<=X; i++)
    {
        for (j=2; j<=X; j++)
            if (sol[j] < sol[j-1])
            {
                temp = sol[j];
                sol[j] = sol[j-1];
                sol[j-1] = temp;
            }
    }
    ofstream fout ("interclasari.out");
    fout << X << '\n';
    for (i=1; i<=X; i++)
        fout << sol[i] << ' ';
    fout.close();
    return 0;
}