#!/usr/bin/env ruby


class A
  attr_accessor :z

  def initialize
    self.z = 'a'
  end

  def self.a
    r = self.new
    return r
  end
end

class B < A

  def initialize
    self.z = 'b'
  end

  def b
    "b"
  end
end

a = A.new
b = B.new

puts a.z
puts b.z
puts
x = B.a
puts x.z