import itertools
N = int(input())

l = [2, 3, 5, 7, 11, 13]
l1 = [4, 6, 8, 9, 10, 12]
lc = []
for i, j in itertools.product(l,l1):
    lc.append(i * j)


print(lc.count(N) / 36)