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// Kacper Orszulak
#include <cstdio>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;

__uint128_t gcd(__uint128_t a, __uint128_t b) {
	while (b) {
		a %= b;
		swap(a, b);
	}
	return a;
}

struct fract_t {
	__uint128_t p = 0, q = 1;
	fract_t& operator+=(const fract_t &another);
};

fract_t& fract_t::operator+=(const fract_t &another) {
	const __uint128_t g = gcd(q, another.q);
	const __uint128_t new_q = q / g * another.q;
	p = p*(new_q/q) + another.p*(new_q/another.q);
	q = new_q;
	return *this;
}

int main(void) {
	size_t n; scanf("%zu", &n);
	vector<vector<size_t>> al(n);
	for (vector<size_t> &r : al) {
		size_t k; scanf("%zu", &k);
		r.resize(k);
		for (size_t &w : r)
			scanf("%zu", &w),
			--w;
	}

	__uint128_t result = 1;
	vector<fract_t> presence(n);
	presence[0].p = 1;
	presence[0].q = 1;
	for (size_t v = 0; v < n; ++v) {
		fract_t &f = presence[v];
		if (f.p == 0)
			continue;
		result = result / gcd(result, f.q) * f.q;

		f.q *= static_cast<__uint128_t>(al[v].size());
		const __uint128_t g = gcd(f.p, f.q);
		f.p /= g;
		f.q /= g;
		for (const size_t w : al[v]) {
			presence[w] += f;
		}
	}

	string s;
	while (result > 0) {
		const char rem = static_cast<char>(result%10);
		s += '0'+rem;
		// printf("%d", rem);
		result /= 10;
	}
	reverse(s.begin(), s.end());
	printf("%s\n", s.c_str());
	// printf("\n");

	return 0;
}