K = int(input())

prime_die = [2, 3, 5, 7, 11, 13]
compo_die = [4, 6, 8, 9, 10, 12]

products = [p * c
        for p in prime_die
        for c in compo_die]

if K in products:
    print(1 / len(products))
else:
    print(0)