https://blog.gongquiz.com/2023/03/17/%ea%b5%90%eb%a5%98%ea%b8%b0%ec%97%90%ec%84%9c-%eb%b6%84%ed%8f%ac%ea%b6%8c%ec%9d%b4%eb%9e%80-%eb%a7%a4%ea%b7%b9-%eb%a7%a4%ec%83%81%ec%9d%98-%ed%99%88slot-%ec%88%98%ea%b0%80-%eb%aa%87-%ea%b0%9c/