#include <fstream>
#include <algorithm>
#define nmax 2000001
using namespace std;

ifstream fin("interclasari.in");
ofstream fout("interclasari.out");

int s[nmax];

int main()
{
    int n,k,i,j,x,nr=0;
    fin>>k;
    for(i=1;i<=k;i++)
     {
        fin>>n;
        for(j=1;j<=n;j++)
        {
            fin>>x;
            s[++nr]=x;
        }
    }
    sort(s+1,s+nr+1);

    fout<<nr<<"\n";
    for(i=1;i<=nr;i++)
        fout << s[i] << " ";
    return 0;
}