#include <bits/stdc++.h>

int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(nullptr);

	int k, n;
	std::cin >> k >> n;
	std::vector<std::vector<int>> tab(k-1);
	std::vector<std::vector<int>> cnts(k);
	cnts[0] = std::vector<int> (n, 0);

	for (int i = 0; i < k - 1; i++) {
		int ns;
		std::cin >> ns;
		cnts[i + 1] = std::vector<int> (ns, 0);
		tab[i].resize(ns);

		for (int j = 0; j < ns; j++) {
			int a;
			std::cin >> a;
			tab[i][j] = a - 1;
		}
	}

	int answer = 0;
	for (int i = k - 1; i >= 0; i--) {
		int local_answer = 0;
		for (int j = 0; j < (int)cnts[i].size(); j++) {
			cnts[i][j] = std::max(cnts[i][j], 1);
			local_answer += cnts[i][j];
		}

		answer = std::max(answer, local_answer);

		if (i == 0) {
			break;
		}

		for (int j = 0; j < (int)cnts[i].size(); j++) {
			int prev = tab[i - 1][j];
			if (prev == -1) {
				continue;
			}

			cnts[i - 1][prev] += cnts[i][j];
		}
	}

	std::cout << answer << "\n";
}