https://blog.faceutil.com/2020/05/07/game_start-%ec%9b%b9%eb%b8%8c%eb%9d%bc%ec%9a%b0%ec%a0%80%ec%97%90%ec%84%9c-%ea%b2%8c%ec%9e%84-%ec%8b%a4%ed%96%89%ed%95%98%ea%b8%b0-%e3%82%b0/