#include <cstdio>
#include <queue>

using namespace std;
priority_queue <int> v;

int main()
{
    FILE *fin=fopen ("interclasari.in","r");
    FILE *fout=fopen ("interclasari.out","w");
    int k,n,s=0;
    int x;
    fscanf (fin,"%d",&k);
    for (;k;k--){
        fscanf (fin,"%d",&n);
        s+=n;
        for (;n;n--){
            fscanf (fin,"%d",&x);
            v.push (-x);
        }
    }
    fprintf (fout,"%d\n",s);
    while (s){
        fprintf (fout,"%d ",-v.top());
        v.pop();
        s--;
    }
    return 0;
}