https://blog.gongquiz.com/2023/05/18/%eb%91%90-%ec%a0%88%eb%8c%80%ec%98%a8%eb%8f%84-t1-t2t1%ef%bc%9ct2%ec%82%ac%ec%9d%b4%ec%97%90%ec%84%9c-%ec%9a%b4%ec%a0%84%ed%95%98%eb%8a%94-%ec%97%94%ec%a7%84%ec%9d%98-%ed%9a%a8%ec%9c%a8%ec%97%90/