require 'observer'

class Game
    include Observable

    def initialize(name)
        @name = name
    end

    def start
        changed
        notify_observers(@name)
    end
end

class Statistic
    attr_reader :startsCount, :lastGame

     def initialize
        @startsCount = 0
        @lastGame = ""
    end

    # callback for observer
    def update(lastGame) 
        @startsCount += 1
        @lastGame = lastGame
    end
end

statistic = Statistic.new
heroes = Game.new("Heroes")
doom = Game.new("Doom")

heroes.add_observer(statistic)
doom.add_observer(statistic)

heroes.start()
doom.start()

puts "lastGame is '#{statistic.lastGame}'"
puts "startsCount is #{statistic.startsCount}"