primes = [2, 3, 5, 7, 11, 13]
composites = {4, 6, 8, 9, 10, 12}

K = int(input())

count = 0

if K != 0:
    for p in primes:
        if p == 0:
            continue
        if K % p != 0:
            continue
        c = K // p
        if c in composites:
            count += 1

probability = count / 36

print("{0:.20f}".format(probability).rstrip('0').rstrip('.') if probability != 0 else "0.00000000000000000")