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#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <queue>
#include <map>
#include <set>
#include <stack>
#include <cmath>
using namespace std; 

long long NWD(long long a, long long b) {
	while (b) {
		long long p = a % b;
		a = b;
		b = p;
	}
	return a;
}
long long NWW(long long a, long long b) {
	return a / NWD(a, b) * b;
}
class Fraction {
public:
	long long nom;
	long long denom;
	Fraction()
		: nom(0), denom(1) {}
	Fraction(long long n)
		: nom(n), denom(1) {}
	Fraction(long long n, long long d)
		: nom(n), denom(d) {}
	void Shorten() {
		long long p = NWD(this->nom, this->denom);
		this->nom /= p;
		this->denom /= p;
	}
	Fraction& operator=(Fraction a) {
		nom = a.nom;
		denom = a.denom;
		return *this;
	}
	Fraction operator+(long long a) {
		return Fraction(nom + a * denom, denom);
	}
	Fraction operator+(Fraction a) {
		Fraction result;
		result.denom = NWW(denom, a.denom);
		result.nom = result.denom / denom * nom + result.denom / a.denom * a.nom;
		result.Shorten();
		return result;
	}
	Fraction operator-(long long a) {
		return Fraction(nom - a * denom, denom);
	}
	Fraction operator-(Fraction a) {
		Fraction result;
		result.denom = NWW(denom, a.denom);
		result.nom = result.denom / denom * nom - result.denom / a.denom * a.nom;
		result.Shorten();
		return result;
	}
	Fraction operator*(long long a) {
		return Fraction(nom * a, denom);
	}
	Fraction operator*(Fraction a) {
		Fraction result;
		result.nom = nom * a.nom;
		result.denom = denom * a.denom;
		result.Shorten();
		return result;
	}
	Fraction operator/(long long a) {
		return Fraction(nom, denom * a);
	}
	Fraction operator/(Fraction a) {
		Fraction result;
		result.nom = nom * a.denom;
		result.denom = denom * a.nom;
		result.Shorten();
		return result;
	}
	bool operator>(Fraction a) {
		long long b = nom / denom, c = a.nom / a.denom;
		if (b != c)
			return b > c;
		else
			return (nom % denom) * a.denom > (a.nom % a.denom) * denom;
	}
	bool operator>=(Fraction a) {
		long long b = nom / denom, c = a.nom / a.denom;
		if (b != c)
			return b >= c;
		else
			return (nom % denom) * a.denom >= (a.nom % a.denom) * denom;
	}
	bool operator==(Fraction a) {
		long long b = nom / denom, c = a.nom / a.denom;
		if (b != c)
			return b == c;
		else
			return (nom % denom) * a.denom == (a.nom % a.denom) * denom;
	}
	bool operator<=(Fraction a) {
		long long b = nom / denom, c = a.nom / a.denom;
		if (b != c)
			return b <= c;
		else
			return (nom % denom) * a.denom <= (a.nom % a.denom) * denom;
	}
	bool operator<(Fraction a) {
		long long b = nom / denom, c = a.nom / a.denom;
		if (b != c)
			return b < c;
		else
			return (nom % denom) * a.denom < (a.nom% a.denom)* denom;
	}

};
Fraction NWW(Fraction a, Fraction b) {
	int denw = NWW(a.denom, b.denom);
	return Fraction(NWW(denw / a.denom * a.nom, denw / b.denom * b.nom), denw);
}

int n_platform;
vector <int> platforms[101];
Fraction part[101];

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
	cin >> n_platform;
	for (int i = 1; i <= n_platform; i++) {
		int r;
		cin >> r;
		for (int j = 0; j < r; j++) {
			int a;
			cin >> a;
			platforms[i].push_back(a);
		}
	}
	part[1] = 1;
	for (int i = 1; i <= n_platform; i++) {
		if (part[i] == 0 || platforms[i].size() == 0)
			continue;
		Fraction add = part[i] / platforms[i].size();
		for (int el : platforms[i])
			part[el] = part[el] + add;
	}
	Fraction result(1);
	for (int i = 1; i <= n_platform; i++) {
		if (platforms[i].size() > 1 && part[i] > 0) {
			result = NWW(result, part[i] * platforms[i].size());
		}
	}
	result.Shorten();
	cout << result.nom;
}