#include <fstream>
#include <vector>
#include <algorithm>
using namespace std;
vector <int> q;
vector <int>::iterator it;
ifstream fin("interclasari.in");
ofstream fout("interclasari.out");
int main()
{
    int n,i,j,k,x;
    fin>>n;
    for(j=1;j<=n;++j)
    {
        fin>>k;
        for(i=1;i<=k;++i)
        {
            fin>>x;
            q.push_back(x);
        }
    }
    sort(q.begin(),q.end());
    fout<<q.size()<<"\n";
    for(it=q.begin();it!=q.end();it++) fout<<*it<<" ";
}