#include <fstream>
#include <vector>
using namespace std;
ifstream in("interclasari.in");
ofstream out("interclasari.out");
vector<int>G[21];
int x,i,k,j,n,p,poz,elem,minn,linii,ind[21];
int main()
{
    in>>k;
    for(i=1; i<=k; i++)
    {
        in>>n;
        if(n) linii++;
        for(j=1; j<=n; j++)
            in>>x,G[linii].push_back(x);
        elem+=n;
    }
    out<<elem<<"\n";
    for(p=1; p<=elem; p++)
    {
        minn=(1<<30);
        for(i=1; i<=linii; i++)
            if(ind[i]<G[i].size() && G[i][ind[i]]<minn)
                minn=G[i][ind[i]],poz=i;
        ind[poz]++;
        out<<minn<<" ";
    }
}