#include <fstream>
#include <vector>

using namespace std;

int K, N, Ni, predecesor;
ifstream fin("interclasari.in");
ofstream fout("interclasari.out");


void insertionSort(int x, vector <int>& v) {
	v.push_back(x);
	int position = v.size()-1;
	for (int i = v.size() - 2; i >= 0; i--) {
		if (x < v[i]) {
			v[i + 1] = v[i];
			position = i;
		}
	}
	v[position] = x;
	return;
}


int main() {
	fin >> K;
	vector <int> r;

	while (K--) {
		fin >> N;
		while (N--) {
			fin >> Ni; 
			insertionSort(Ni, r);
		}
	}

	fout << r.size() << '\n';

	for (auto& x : r)
		fout << x << " ";

	fin.close(); fout.close();

	return 0;
}