#include <fstream>
#include <set>

using namespace std;

ifstream f("interclasari.in");
ofstream g("interclasari.out");

int K, N;

multiset < int > my_set;

int main()
{
    f >> K;

    for(int i = 1; i <= K; ++i)
    {
        f >> N;

        int el;

        for(int j = 1; j <= N; ++j)
        {
            f >> el;
            my_set.insert(el);
        }
    }

    g << my_set.size() << '\n';

    multiset < int > :: iterator it;

    for(it = my_set.begin(); it != my_set.end(); ++it) g << *it << ' ';


}