#include<fstream>
#include<algorithm>
using namespace std;

int n=1,i,k,t,a[20000005];

int main()
{
  ifstream cin("interclasari.in");
  ofstream cout("interclasari.out");

  cin>>k;
  while(k--)
  {
    cin>>t;
    for(i=n;i<n+t;i++)
    cin>>a[i];
    n+=t;
  }

  sort(a+1,a+n);

  cout<<n-1<<'\n';
  for(i=1;i<n;i++)
  cout<<a[i]<<' ';

 return 0;
}