https://blog.gongquiz.com/2022/07/25/%ea%b7%b8%eb%a6%bc%ec%9d%98-%ec%8b%a0%ed%98%b8%ed%9d%90%eb%a6%84%ec%84%a0%eb%8f%84%ec%97%90%ec%84%9c-c-r%ec%9d%98-%ea%b0%92%ec%9d%80-%ea%b3%b5%ec%a1%b0%eb%83%89%eb%8f%99%ea%b8%b0%ea%b3%84%ec%82%b0/