#include <fstream>
#include <vector>
#include <algorithm>

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


int k,n,x;


vector <int> a;

int main()
{
    fin>>k;
    for(int i=1;i<=k;i++)
    {
        fin>>n;
        for(int j=1;j<=n;j++)
        {
            fin>>x;
            a.push_back(x);
        }
    }
    sort(a.begin(),a.end(),greater<int>());
    fout<<a.size()<<"\n";
    while(!a.empty())
    {
        fout<<a.back()<<" ";
        a.pop_back();
    }

}