#include<iostream>
#include<vector>

int gcd(long long x, long long y) {
	while (true) {
		x = x % y;
		if (x == 0)
			return y;
		y = y % x;
		if (y == 0)
			return x;
	}
}

int main() {
	int gear_num;
	std::cin >> gear_num;

	std::vector<long long> v(gear_num);
	for (int i = 0; i < gear_num; i++) {
		std::cin >> v[i];
	}


	long long g = gcd(v.front(), v.back());

	std::cout << v.back() / g << "/" << v.front() / g << std::endl;
	return 0;
}