#include<fstream>
#include<algorithm>
using namespace std;
ifstream cin("interclasari.in");
ofstream cout("interclasari.out");
int k,i,j,n,v[20000001],a,x;
int main()
{
    cin>>k;
    for(i=1;i<=k;i++)
    {
        cin>>n;
        for(j=1;j<=n;j++)
        {
          cin>>x;
          a++;
          v[a]=x;
        }

    }
    sort(v+1,v+a+1);
    cout<<a<<"\n";
    for(i=1;i<=a;i++)
    cout<<v[i]<<" ";
}