def gcd(a, b):
    if b == 0:
        return a
    return gcd(b, a % b)

t = [int(input()) for i in range(3)]
numer = t[0] * t[1] * t[2]
denom = gcd(t[1] * (t[2] - t[0]), t[0] * (t[2] - t[1]))
common = gcd(numer, denom)

print(numer // common, denom // common, sep="/")