https://ling-lingchinese.com/2015/02/18/chinese-riddle-3-%e4%b8%ad%e5%9b%bd%e8%b0%9c%e8%af%ad3-%e7%8c%9c%e7%8c%9c%e6%88%91%e6%98%af%e8%b0%81-caicai-wo-shi-shei-guess-who-i-am/