https://knightzone.studio/2020/09/26/20994/2020-%e9%90%b5%e4%ba%ba%e8%b3%bd%e4%b8%bb%e9%a1%8c%e3%80%8c%e4%bb%a5-kotlin-%e7%82%ba%e4%b8%bb%e8%a6%81%e8%aa%9e%e8%a8%80%e5%bb%ba%e6%a7%8b%e5%9f%ba%e6%9c%ac%e7%9a%84-online-judge-%e7%b3%bb-26/