# -*- coding:utf-8 -*-
#全探索も計算量的にいけるなら躊躇なく書かなければな
import itertools
if __name__ == "__main__":
	k = input()
	a = [2,3,5,7,11,13]
	b = [4,6,8,9,10,12]
	c = [0,1,2,3,4,5]
	ans = 0
	for i, j in itertools.product(c,repeat = 2):
		if a[i] * b[j] == k:
			ans += 1
	print ans / 36.0