import decimal

K = int(input())

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

count = 0

for p in prime_dice:
    if K != 0 and (K % p) == 0:
        c = K // p
        if c in composite_set:
            count += 1

if count == 0:
    print("0.00000000000000000")
else:
    decimal.getcontext().prec = 20
    prob = decimal.Decimal(count) / decimal.Decimal(36)
    formatted = format(prob, '0.18f')
    print(formatted)