#include <bits/stdc++.h>

using namespace std;

const int MAXN = 2e7;

int v[MAXN];

int main()
{
    int n, k, m;
    ifstream fin("interclasari.in");
    m = 0;
    fin >> n;
    for (int i = 0; i < n; ++i) {
      fin >> k;
      for (int j = 0; j < k; ++j)
        fin >> v[m++];
    }
    fin.close();
    sort(v, v + m);
    ofstream fout("interclasari.out");
    fout << m << '\n';
    for (int i = 0; i < m; ++i)
      fout << v[i] << " ";
    fout.close();
    return 0;
}