r={}
a=[8,12,16,18,20,24,27,28,30,36,40,42,44,45,50,52,56,60,63,66,70,78,84,88,99,104,110,117,130,132,156]
a.each{|i|r[i] = 1}
b=[12,18,20,24,30]
b.each{|i|r[i] += 1}
c = gets.to_i
if r[c]
	puts r[c]/36.0
else
	puts 0
end