#!/usr/bin/env python3
from fractions import Fraction
a = Fraction(input())
b = Fraction(input())
c = Fraction(input())
t = 0
dt = 1 / (1/a - 1/b)
while True:
    t += dt
    assert t / a % 1 == t / b % 1
    if     t / a % 1 == t / b % 1 == t / c % 1:
        break
print('{}/{}'.format(t.numerator, t.denominator))