#include <iostream>
#include <algorithm>
using namespace std;
typedef long long ll;

ll GCD(int a, int b){
  if(b == 0)
    return a;
  return GCD(b, a % b);
}

ll calcGCD(int a, int b){
  if(a < b)
    swap(a, b);
  return GCD(a, b);
}

ll calcLCM2(ll a, ll b){
  if(a < b)
    swap(a, b);
  return a / GCD(a, b) * b;
}

ll calcLCM3(ll a, ll b, ll c){
  return calcLCM2(calcLCM2(a, b), c);
}

int main(){
  int t1, t2, t3;
  ll v1, v2, v3;
  cin >> t1 >> t2 >> t3;
  ll numer = calcLCM3(t1, t2, t3);
  v1 = numer / t1 + numer / t2;
  v2 = numer / t2 + numer / t3;
  v3 = numer / t3 + numer / t1;
  ll denom = calcGCD(v1, v2);
  denom = max(denom, calcGCD(v2, v3));
  denom = max(denom, calcGCD(v3, v1));
  ll tmp = calcGCD(numer, denom);
  cout << numer / tmp << "/" << denom / tmp << endl;
}