https://qooah.com/2016/03/12/alphago-%e5%ae%a3%e4%bd%88%e6%88%b0%e5%8b%9d%e5%9c%8d%e6%a3%8b%e4%b9%9d%e6%ae%b5%e9%ab%98%e6%89%8b%e6%9d%8e%e4%b8%96%e7%9f%b3/