规则Rules：
填入1~9，使得每行、列、宫内，以及每一组由灰色线条连结的格子里的数字不重复。
Write 1~9 to make numbers no repeated in each Row, Column, Box, and each group of cells linked by the curve.
◆管道数独规则 Rule of Sudo-Kurve
◆在线涂鸦 Draw it Online
◆在线做 Do it by CTC
◆在线做 Do it by Penpa
