Manuel does a weekly exercise program consisting of cardiovascular work and weight training. Each week, he exercises for at least 7 hours. He spends at most 12 hours doing cardiovascular work and at most 4 hours on weight training. Let (x) denote the time (in hours) that Manuel spends doing cardiovascular work and (y) denote the time (in hours) that he spends on weight training. Shade the region corresponding to all values of (x) and (y) that satisfy these requirements.