#include <fstream>
#include <algorithm>
#define NUM 2000005
using namespace std;
int v[NUM];
int n, k, lng, val;
int main()
{
    ifstream f("interclasari.in");
    ofstream g("interclasari.out");
    f >> n;
    for(int i = 0; i < n; ++i)
    {
        f >> k;
        for(int j = 0; j < k; ++j)
        {
            f >> val;
            v[lng++] = val;
        }
    }
    sort(v, v + lng);
    g << lng << "\n";
    for(int i = 0; i < lng; ++i)
        g << v[i] << " ";
    f.close();
    g.close();
}