#include <fstream>
#include <algorithm>
#include <cstdio>
using namespace std;
FILE *fin=fopen("interclasari.in","r");
ofstream fout("interclasari.out");
long long n,i,s,t,v[1000000*20],k,j;
int main()
{
    fscanf(fin,"%lld",&n);
    for(i=1;i<=n;i++)
    {
        fscanf(fin,"%lld",&t);
        for(j=1;j<=t;j++)
           {
               s++;
               fscanf(fin,"%lld",&v[s]);
           }
    }

    fout<<s<<"\n";
    std::sort(v+1,v+1+s);
    for(i=1;i<=s;i++)
       fout<<v[i]<<" ";
    return 0;
}