Case Closed Episode 473 SUB at Gogoanime

Synopsis: Shinichi solves the riddle and heads to the school and finds the next riddle on a stop sign. The letter contains a mixture of kanji, and mahjong symbols and when read, pronounces Beika City Hall. Once there, Shinichi finds a sign on a pole with the message "S → W". Shinichi presumes it means the sunset and assumes his father created the riddle for his entertainment.