#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std;
int i,n,k,j,m,s,dr,x,ok,y,sol,v[20000100];


int main()
{
    freopen ("interclasari.in","r",stdin);
    freopen ("interclasari.out","w",stdout);

    scanf("%d",&n);
    int cont=0;

    for(i=1;i<=n;i++)
    {
        scanf("%d",&m);

        for(j=1;j<=m;j++)
        {
            cont++;
            scanf("%d",&v[cont]);
        }
    }

    sort(v+1,v+1+cont);
    printf("%d\n",cont);
    for(i=1;i<=cont;i++)
    {
        printf("%d ",v[i]);
    }
}