module Inject
	def inject(val)
		each do | element |
			val = yield(val, element)
		end
		val
	end

	def somme
		inject(0) do | s, element | 
			s + element
		end
	end

	def produit
		inject(1) do | p, element |
			p * element
		end
	end
end

class Impairs
	include Inject
	def initialize(n)
		@cardinal = n
	end

	def each
		i = 1
		@cardinal.times do
			yield i
			i = i +2
		end
	end
end

class Integer
	def premiers_impairs
		Impairs.new(self)
	end
end

def carre(n)
	n.premiers_impairs.somme
end

3.premiers_impairs.each do | i |
	puts i.to_s
end

puts "Somme : #{3.premiers_impairs.somme}"
puts "Produit : #{3.premiers_impairs.produit}"

puts "Carré de 3 : #{carre(3)}"