K = int(input())
sosuu = [2, 3, 5, 7, 11, 13]
gousei = [4, 6, 8, 9, 10, 12]

p = 0

for i in range(6):
    for j in range(6):
        if sosuu[i] * gousei[j] == K:
            P += 1

print(p / 36)