#include <bits/stdc++.h>
using namespace std;

long long lcm(long long a, long long b) {
	return a / __gcd(a, b) * b;
}

int main() {
	long long a, b, c;
	cin >> a >> b >> c;

	long long p1 = b - a;
	long long q1 = a * b;

	long long p2 = c - b;
	long long q2 = b * c;

	long long l = lcm(q1, q2);
	p1 *= l / q1;
	p2 *= l / q2;

	long long x = l;
	long long y = __gcd(p1, p2);
	long long g = __gcd(x, y);
	x /= g;
	y /= g;

	printf("%lld/%lld\n", x, y);
}