gistfile1.rb

roles = %w(participant admin organizer)
users = %w(hans fred fritz)
conferences = %w(osc13 dsp14 lala)

roles.each do |role|
  users.each do |user|
    conferences.each do |conf|
      if role == "organizer" || role == 'admin'
        puts "YO YO YO"
      else
        puts "#{user}.add_role #{role}, #{conf}"
      end
    end
  end
end