module main;

import std;

void main()
{
	// 入力
	int N = readln.chomp.to!int;
	auto Z = readln.split.to!(ulong[]);
	// 答えの計算
	ulong g = gcd(Z[0], Z[1]);
	ulong a = Z[1] / g, b = Z[0] / g;
	foreach (i; 1 .. N - 1) {
		a *= Z[i + 1];
		b *= Z[i];
		g = gcd(a, b);
		a /= g;
		b /= g;
	}
	// 答えの出力
	writefln("%d/%d", a, b);
}