#include <bits/stdc++.h>
using namespace std;
ifstream f ("interclasari.in");
ofstream g ("interclasari.out");
int t,i,j,x,v[20000001],k,n;
int main()
{
    f>>t;
    for(i=1;i<=t;++i)
    {
        f>>n;
        for(j=1;j<=n;++j)
        {
            f>>x;
            v[++k]=x;
        }
    }
    sort(v+1,v+k+1);
    g<<k<<'\n';
    for(i=1;i<=k;++i) g<<v[i]<<' ';
    return 0;
}