#include <bits/stdc++.h> 

using namespace std;

#define FOR(i, a, b) for(int i = (a); i < (b); i++)
#define RFOR(i, a, b) for(int i = (a) - 1; i >= (b); i--)
#define SZ(a) int(a.size())
#define ALL(a) a.begin(), a.end()
#define PB push_back
#define MP make_pair
#define F first
#define S second

typedef long long LL;
typedef vector<int> VI;
typedef pair<int, int> PII;
typedef double db;

int main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	
	int ab, ac, bd;
	while (cin >> ab >> ac >> bd)
	{
		int num = ab * ac, den = bd - ac, g = gcd(num, den);
		cout << num / g << "/" << den / g << "\n";
	}
	return 0;
}