#include <set>
///#include "iostream"
#include <fstream>

using namespace std ;

ifstream cin ("interclasari.in") ;
ofstream cout ("interclasari.out") ;

int t, n ;

int main ()
{

    multiset < int > S ;
    int x, nn = 0 ;

    cin >> t ;

    for (int tt = 0; tt < t; ++tt) {
        cin >> n ;

        for (int i = 0; i < n; ++i) {


            cin >> x ;

            S.insert(x) ;

        }

        nn += n ;

    }

    cout << nn << '\n' ;

    for (int item : S)
        cout << item << ' ' ;


    return 0 ;

}