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

for(i=1;i<=k;i++)
{
    f>>n;
    for(j=1;j<=n;j++){
    f>>x;
    v[a]=x;
    a++;}
}
sort(v+1,v+a+1);
g<<a<<'\n';
for(i=2;i<=a;i++)
g<<v[i]<<" ";

    return 0;
}