#include <fstream>
#include <algorithm>
#include <list>
using namespace std;
ifstream f("interclasari.in");
ofstream g("interclasari.out");
int i,j,N,M,x;
list<int> v;
int main()
{

    list<int>::iterator it=v.begin();
    f>>N;
    f>>M;
    for (j=1;j<=M;++j)
            f>>x,v.push_back(x);
    for (i=1;i<N;++i)
        {
            it=v.begin();
            f>>M;
            for (j=1;j<=M;++j)
                {
                    f>>x;
                    while (*it<x)++it;
                    v.insert(it,x);
                }
        }
        g<<v.size()<<'\n';
    for (it=v.begin();it!=v.end();++it)
        g<<*it<<" ";
    return 0;
}