K = int(input())

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

count = 0
for j in range(6):
    for i in range(6):
        if K == primeDice[j] * compositeDice[i]:
            count += 1

print(count / 36)