https://blog.gongquiz.com/2020/11/30/%ea%b9%8a%ec%9d%b4-5-0m%ec%9d%b8-%ec%96%b4%eb%96%a4-%eb%b0%80%ed%8f%90%ed%83%b1%ed%81%ac-%ec%95%88%ec%97%90-%eb%ac%bc%ec%9d%b4-3-0m-%ec%b1%84%ec%9b%8c%ec%a0%b8-%ec%9e%88%ea%b3%a0-2kgf-cm2%ec%9d%98/