The rule at Anna's house is that if she eats all of her vegetables and does all of her chores each day, she earns 2 hours of internet time which she can save. Anna started her week with 3 hours saved. If she eats all of her vegetables and does all of her chores each day for 4days straight, how many hours does she have after the 4 days if she uses 6 hours of her internet time?