Look up the picture A , the big wood is cut into many small ones. As we know, a cuboid has three attributes: Length, Width and Height. In the picture B, C, D, there are different. The problem is so easy that you just need to count the kinds of the cuboids which can be cut from the big one. When we cut the big one into so many small one, we give every one a number to mark which is 1×1×1. Look at the picture B and C, they have the same length, width and height, but the marking numbers they have are different from each other, so B is different from C. B and D have the different attributes (any one attribute of the length, width and height is different), so they are also different.