#include<iostream>
using namespace std;
long T1,T2,T3;
long gcd(long a,long b){return b?gcd(b,a%b):a;}
main()
{
	cin>>T1>>T2>>T3;
	long A=T2*(T3-T1),B=T3*(T2-T1);
	long G=gcd(A,B);
	long k=B/G,l=A/G;
	long ta=T1*T2*k,tb=T2-T1;
	long g=gcd(ta,tb);
	ta/=g;tb/=g;
	cout<<ta<<"/"<<tb<<endl;
}