#include<fstream>
#include<algorithm>
using namespace std;
ifstream f("interclasari.in");
ofstream g("interclasari.out");
int i,n,j,nr,m,v[20000100];
int main()
{
    f>>n;
    for(i=1;i<=n;++i)
    {
        f>>m;
        for(j=1;j<=m;++j)
        f>>v[++nr];
    }
    sort(v+1,v+nr+1);
    g<<nr<<'\n';
    for(i=1;i<=nr;++i)
    g<<v[i]<<' ';
    return 0;
}