https://blog.gongquiz.com/2023/01/08/%eb%8c%80%ec%84%b1%eb%a7%88%ec%9d%b4%eb%a7%a5-%ec%82%ac%ed%83%90-%ec%9e%84%ec%a0%95%ed%99%98-nct%ea%b0%80-%eb%ad%90%ec%95%bc-whats-nct-l/