#include <algorithm>
#include <fstream>
#include <vector>

using namespace std;

ifstream f ("interclasari.in");
ofstream g ("interclasari.out");

int n, k, x;
vector <int> v;

int main() {
    f >> n;
    for (int i = 1; i <= n; ++i) {
        f >> k;
        for (int j = 1; j <= k; ++j) {
            f >> x;
            v.push_back(x);
        }
    }

    sort (v.begin(), v.end());
    g << v.size() << '\n';

    for (vector <int> :: iterator it = v.begin(); it != v.end(); ++it) {
        g << *it << " ";
    }
    return 0;
}