#include <iostream>
#include <fstream>

#define KMAX 20
#define INFINIT 1000000000 //un miliard, 10^9

using namespace std;

ifstream fin ("interclasari.in");
ofstream fout ("interclasari.out");

int *v[KMAX];
int ct[KMAX];
int dim[KMAX];

int main()
{
    int K;
    fin >> K;

    int nrElem = 0;
    for(int i = 0; i < K; i++){

        int N;
        fin >> N;
        nrElem += N;
        dim[i] = N;

        v[i] = (int *) malloc(N * sizeof(int));

        for(int j = 0; j < N; j++){
            fin >> v[i][j];
        }
    }

    fout << nrElem << "\n";

    for(int rep = 1; rep <= nrElem; rep++){
        int mn = INFINIT;
        int pozMn;

        for(int i = 0; i < K; i++){
            if(ct[i] < dim[i] && v[i][ ct[i] ] < mn){
                mn = v[i][ ct[i] ];
                pozMn = i;
            }
        }

        fout << mn << ' ' ;
        ct[pozMn]++;
    }

    return 0;
}