Pokémon: Ruby version - Seafloor Cavern (last boulders puzzle)

My last video was disabled with all my very first account, so I've reuploaded this famous guide which a lot of Pokémon Ruby players praised. It's about last boulders moving in Pokémon: Ruby version's Seafloor Cavern area, which turned out to be puzzle one. But I solved that! So, here you go...