In this challenge, you must finish the program so that the player chooses to buy item 1, 2, or 3. That item is added to the hero's inventory only if the player has enough money. Also, the shopkeeper should say something when the purchase is made or not able to be made. CHALLENGE MODE: If a player buys more than one of an item, make those items appear in the inventory in alphabetical order instead of just in the order they were bought.
