https://blog.faceutil.com/2017/05/06/%ec%9c%88%eb%8f%84%ec%9a%b0-%eb%b9%84%ec%8a%a4%ed%83%80-7-%ec%97%90%ec%84%9c-%eb%a7%88%eb%a9%94-%ec%8b%a4%ed%96%89%ed%95%98%ea%b8%b0-mame-%ec%8b%a4%ed%96%89%ed%95%98%ea%b8%b0-%ea%b5%ac%eb%b2%84-2/