#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

vector <int> v[22];

int k, n[22], p[22], m;

int main()
{
    ifstream fin ("interclasari.in");
    ofstream fout ("interclasari.out");
    fin >> k;
    for(int e = 1; e <= k; e++)
    {
        fin >> n[e];
        for(int i = 1; i <= n[e]; i++)
        {
            int el;
            fin >> el;
            v[e].push_back(el);
        }
        m += n[e];
    }
    fout << m << "\n";
    for(int i = 1; i <= m; i++)
    {
        int mi = -1, po;
        for(int j = 1; j <= k; j++)
            if(p[j] < n[j] && (v[j][p[j]] < mi || mi == -1))
            {
                mi = v[j][p[j]];
                po = j;
            }
        p[po]++;
        fout << mi << " ";
    }
    return 0;
}