#!/usr/bin/python
from fractions import gcd, Fraction
lcm = lambda a, b: a * b / gcd(a, b)
lcmx = lambda arr: reduce(lcm, arr)

t1 = int(raw_input())
t2 = int(raw_input())
t3 = int(raw_input())
lm = lcmx((t1, t2, t3))
vs = map(lambda t: lm / t, (t1, t2, t3))
for d in reversed(xrange(max(t1, t2, t3))):
    r1, r2, r3 = map(lambda v: v % d, vs)
    if r1 == r2 or r1 == d-r2:
        if r1 == r3 or r1 == d-r3:
            break
res = Fraction(lm, d)
print '{}/{}'.format(res.numerator, res.denominator)