#include <fstream>
#include <algorithm>
using namespace std;
ifstream fin("interclasari.in");
ofstream fout("interclasari.out");
long long n,i,s,t,v[1000000*20],k,j;
int main()
{
    fin>>n;
    for(i=1;i<=n;i++)
    {
        fin>>t;
        for(j=1;j<=t;j++)
           {
               s++;
               fin>>v[s];
           }
    }
     std::sort(v+1,v+1+s);
    fout<<s<<"\n";
    for(i=1;i<=s;i++)
       fout<<v[i]<<" ";
    return 0;
}