from math import gcd

def lcm(a, b):
    return a // gcd(a, b) * b

def main():
    t1 = int(input())
    t2 = int(input())
    t3 = int(input())

    p1, q1 = t1 * t2, t2 - t1
    p2, q2 = t1 * t3, t3 - t1

    q = lcm(q1, q2)
    p1 *= q // q1
    p2 *= q // q2
    p = lcm(p1, p2)

    g = gcd(p, q)
    print("{}/{}".format(p // g, q // g))

if __name__ == "__main__":
    main()