t1 = int(input())
t2 = int(input())
t3 = int(input())

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

x = t3 * t2 * t1
y = gcd((t2-t1) * t3, (t3-t2) * t1)
z = gcd(x, y)

print('%d/%d' % (x/z, y/z))