#include <iostream>
#include <vector>
#include <cstdio>
#include <sstream>
#include <map>
#include <string>
#include <algorithm>
#include <queue>
#include <cmath>
#include <functional>
#include <set>
#include <ctime>
#include <random>
#include <chrono>
using namespace std;

template<class T> istream& operator >> (istream& is, vector<T>& vec){for(T& val: vec) is >> val; return is;}
template<class T> istream& operator ,  (istream& is, T& val){ return is >> val;}
template<class T> ostream& operator << (ostream& os, const vector<T>& vec){for(int i=0; i<vec.size(); i++) os << vec[i] << (i==vec.size()-1?"":" "); return os;}
template<class T> ostream& operator ,  (ostream& os, const T& val){ return os << " " << val;}
template<class T> ostream& operator >> (ostream& os, const T& val){ return os << " " << val;}

long long gcd(long long a, long long b){
	if(b==0) return a;
	return gcd(b, a%b);
}

long long lcm(long long a, long long b){
	if(a<b) swap(a,b);
	if(b==1) return a;
	return a * (b/gcd(a,b));
}


long long extgcd(long long a, long long b, long long &x, long long &y){
	long long d=a;
	if(b!=0){
		d = extgcd(b, a%b, y, x);
		y -= (a/b) * x;
	}else{
		x = 1;
		y = 0;
	}
	return d;
}

int main(){
	vector<int> t(3); cin >> t;
	long long l = lcm(t[0], lcm(t[1],t[2]));
	
	long long g = gcd(l/t[0]-1, gcd(l/t[1]-1,l/t[2]-1));

	cout << l << "/" << g << endl;

	return 0;
}