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，并且每个宫内不一定包含所有类型的数字。
Write 1~7 to make numbers no repeated in each Row, Column and Box. The Box may be irregular, and may not contain all kinds of the numbers.
◆例题Example
◆在线做Do it by CTC
◆在线做Do it by Penpa
