K = int(input())
ans = 0
for i in [2, 3, 5, 7, 11, 13]:
    cnt = 0
    for j in [4, 6, 8, 9, 10, 12]:
        if i * j == K:
            cnt += 1
    ans += 1/6 * (1/6 * cnt)
print(ans)