规则Rules：
填入1~7，使得每行、列、宫内数字不重复，宫可能是锯齿状的。
Fill the grid with 1~7, make numbers no repeated in each Row, Column and Box. The Box may be irregular.
作者Author：Lvkaiyi0811
◆例题Example
◆在线做 Do it by CTC
◆在线做Do it by Penpa
