规则Rules：
标准数独基础上，"大"字格填5或6，"中"字格填3或4，"小"字格填1或2。
Classic rules applied. Additionally, 大 means 5 or 6, 中 means 3 or 4, 小 means 1 or 2.
◆例题 Examples
◆在线涂鸦 Draw it Online
◆在线做 Do it by CTC
◆在线做 Do it by Penpa
