#!/usr/bin/env python3
import math
from fractions import Fraction
def lcm(a, b):
    return a * b // math.gcd(a, b)
def qlcm(p, q):
    a = p.numerator * q.denominator
    b = p.denominator * q.numerator
    c = p.denominator * q.denominator
    return Fraction(lcm(a, b), c)
a = Fraction(input())
b = Fraction(input())
c = Fraction(input())
p = 1 / (1/a - 1/b)
q = 1 / (1/b - 1/c)
t = qlcm(p, q)
print('{}/{}'.format(t.numerator, t.denominator))