Jichang Xueshe, the most important thing is persistence!Jichang learned how to shoot from Feiwei, and succeeded three years later. When an arrow is shot, it can shoot through three view planes of a cube with side length N at the same time, and the coordinates of the view planes penetrated are the same. The unit cube hit by the arrow will disappear immediately. Do you know how much volume is left in the cube after Jichang shoots the M arrow?The three view planes of the cube are assigned coordinates in the same way. For example, the coordinates of the cube with side length of 3 and the three view planes are shown in the following figure.
Jichang Xueshe, the most important thing is persistence! Jichang learned how to shoot from Feiwei, and succeeded three years later. When an arrow is shot, it can shoot through three view planes (front view, right view and top view) of a cube with side length N at the same time, and the coordinates of the view planes penetrated are the same. The unit cube (side length is 1) hit by the arrow will disappear immediately. Do you know how much volume is left in the cube after Jichang shoots the M arrow? The three view planes of the cube are assigned coordinates in the same way. For example, the coordinates of the cube with side length of 3 and the three view planes are shown in the following figure.
（图片来源网络，侵删）
