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

ts = map(int, (raw_input() for _ in xrange(3)))
lm = lcmx(ts)
vs = map(lambda t: lm / t, ts)
for d in reversed(xrange(1, max(ts)/2+1)):
    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)