# -*- coding: utf-8 -*-

k = int(input())
so = [2,3,5,7,11,13]
go = [4,6,8,9,10,12]
sogo = [[0 for i in range(6)] for j in range(6)]
for i in range(6):
    for j in range(6):
        sogo[i][j] = so[i] * go[j]
knum = 0
for i in range(6):
    for j in range(6):
        if sogo[i][j] == k:
            knum += 1
print(knum/36)