#include<fstream>
#include<algorithm>
using namespace std;

#define BM 1000005

int n,k;
int r[BM*20],dim;

int main (){
    int i,j;
    ifstream f("interclasari.in");
    ofstream g("interclasari.out");
    f>>k;
    for(i=1;i<=k;++i){
        f>>n;
        for(j=1;j<=n;++j)f>>r[++dim];
    }
    sort(r+1,r+dim+1);
    g<<dim<<'\n';
    for(i=1;i<=dim;++i)g<<r[i]<<' ';
    return 0;
}