Can you guide me through solving this problem: Linda is painting her bedroom. Her bedroom has 4 walls, with the room being 20 feet wide by 20 feet long by 8 feet tall. One wall has a 3-foot by 7-foot doorway. A second wall has a 6-foot by 4-foot window. A third wall has a 5-foot by 7-foot doorway to a walk-in-closet. And the fourth wall is completely solid. What is the total area of wall space that Linda will have to paint?