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

ll gcd(ll a, ll b){
    return b == 0 ? a : gcd(b, a%b);
}

ll lcm(ll a, ll b){
    return a*b/gcd(a,b);
}

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

    ll mox, chx, moy, chy;

    mox = lcm(a,b);
    moy = lcm(b,c);
    chx = mox/a - mox/b;
    chy = moy/b - moy/c;

    // needless?
    ll g = gcd(mox, chx);
    mox /= g, chx /= g;
    g = gcd(moy, chy);
    moy /= g, chy /= g;

    if(mox == moy && chx == chy){
        cout << mox << "/" << chx << endl;
    }else{
        ll mo = lcm(mox, moy);
        chx *= mo/mox, chy *= mo/moy;
        ll ch = abs(chx-chy);
        g = gcd(ch, mo);
        ch /= g, mo /= g;
        cout << mo << "/" << ch << endl;
    }

    return 0;
}