#include <cstdio>
#include <cstring>
#include <algorithm>
#define MaxN 20000001
#define INF 2140000000

using namespace std;

FILE *IN,*OUT;
int T,N,P=0,v[MaxN];
int main()
{
    IN=fopen("interclasari.in","r");
    OUT=fopen("interclasari.out","w");

	fscanf(IN,"%d",&T);
	for(int t=1;t<=T;t++)
	{
		fscanf(IN,"%d",&N);
		for(int i=1;i<=N;i++)
			fscanf(IN,"%d",&v[++P]);
	}
    sort(v+1,v+1+P);
	fprintf(OUT,"%d\n",P);
	for(int i=1;i<=P;i++)
		fprintf(OUT,"%d ",v[i]);
    return 0;
}