#include<fstream>
using namespace std;
ifstream f("interclasari.in"); ofstream g("interclasari.out");
int n,i,m,k,j,l,r,t,v[1000001],a[5000001],b[5000001];
int main()
{   f>>n;
    while(n--)
    {   f>>m;
		for(j=1;j<=m;j++) f>>v[j];
          for(t=0,j=l=1;j<=k&&l<=m;)
			  if(a[j]>v[l]) b[++t]=v[l++]; else b[++t]=a[j++];
          for(;j<=k;b[++t]=a[j++]);
          for(;l<=m;b[++t]=v[l++]);
          for(k+=m,j=1;j<=k;j++) a[j]=b[j];
    }
    g<<k<<'\n';
    for(i=1;i<=k;i++) g<<a[i]<<' ';
	g.close(); return 0;
}