#include <iostream>
#include <fstream>
#include <algorithm>

using namespace std;
int k;
int m;
int n;
int v[5000001];

int main ()
{
    ifstream f("interclasari.in");
    ofstream g("interclasari.out");
    f>>k;
    n=0;
    for ( int i=1;i<=k; i++ )
    {
        f>>m;
        for (int j=1; j<=m; j++)
        {
            n++;
            f>>v[n];
        }
    }
    sort(v+1,v+n+1);
    g<<n<<"\n";
    for ( int i=1; i<=n; i++)
        g<<v[i]<<" ";
    f.close();
    g.close();
    return 0;

}