#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; 
}