#include "math.h"
#include <algorithm>
#include <complex>
#include <cstdio>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <string>
#include <vector>
#define ifor(i, a, b) for (int i = (a); i < (b); i++)
#define rfor(i, a, b) for (int i = (b)-1; i >= (a); i--)
#define rep(i, n) for (int i = 0; i < (n); i++)
#define rrep(i, n) for (int i = (n)-1; i >= 0; i--)
using namespace std;
using lli = long long int;
struct frac {
    lli up, down;
    frac(lli a, lli b)
    {
        up = a / __gcd(a, b);
        down = b / __gcd(a, b);
    }
    frac minus(frac l, frac r)
    {
        return frac(abs(l.up * r.down - r.up * l.down), l.down * r.down);
    }
};
int main()
{
    lli t[3];
    cin >> t[0] >> t[1] >> t[2];
    sort(t, t + 3);
    frac a(1, t[0]);
    frac b(1, t[1]);
    frac c(1, t[2]);
    frac d = a.minus(a, b);
    frac e = a.minus(a, c);
    lli f = d.down / __gcd(d.down, e.down) * e.down;
    lli g = e.up * d.down / __gcd(d.down, e.down);
    lli h = d.up * e.down / __gcd(d.down, e.down);
    cout << f << "/" << __gcd(g, h) << endl;
}