Earlier it was known to us that raftel is at the end of the grand line and that the person has to follow the log to get there. But now the dog king told that the point of incidence of the road poneglyphs is raftel. So exactly what does he mean? Don't we have to follow the log anymore? Or is the 4th road poneglyph at the end of the grand line? I didn't quite get it. Please explain.