#include <fstream>
#include <algorithm>
#include <vector>
using namespace std;
ifstream f("interclasari.in");
ofstream g("interclasari.out");
int i,j,N,M,x,v[20000005],k;
int main()
{
    f>>N;
    for (i=1;i<=N;++i)
        {
           f>>M;
           for (j=1;j<=M;++j)
                f>>v[++k];
        }
    sort(v+1,v+k+1);
    g<<k<<'\n';
    for (i=1;i<=k;++i)
        g<<v[i]<<" ";
    return 0;
}