https://blog.gongquiz.com/2022/11/10/%ec%b2%9c%ed%95%98%ec%9e%a5%ec%82%ac-%ec%a4%91%ec%9e%a5%eb%b9%84-%ec%99%b8-12%ea%b3%a1-60%eb%b6%84-l-%ed%83%80%ec%9a%94-%eb%85%b8%eb%9e%98%eb%b0%a9-l-%ed%83%80%ec%9a%94-%ec%94%bd%ec%94%bd%ea%b7%b9/