0704 문제 끝장내기 BSBC 2021.07.04 14:09 https://www.youtube.com/watch?v=TvSDwygw09U + 139 https://www.youtube.com/channel/UCcNAi0Cztgxw3fWgbfTdwrw/videos + 317 0704 문제 끝장내기