On both sides of the road in Leather City, there are all paper grid training courses, both on the second and third floors. As long as you look up, there are advertisements posted on the windows, and you can see at a glance, depending on which one you choose. Personally, I have some suggestions for you. If you choose, you can choose the board that meets the factory to produce paper grids, so that you can really learn something. If it is to fix those bags, it is not very useful.