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

K = int(input())

m_dict = {}

primes = [2,3,5,7,11,13]
composites = [4,6,8,9,10,12]

for p in primes:
    for c in composites:
        m = p*c
        if m in m_dict:
            m_dict[m] += 1
        else:
            m_dict[m] = 1

if K in m_dict:
    print(m_dict[K]/36)
else:
    print(0.0)