规则Rules：
标准数独基础上，每个区域内数字不重复，角标是区域内数字之和。
Classic rules applied. Additionally, numbers cannot repeat in each region, clue is the sum of all the numbers in that region.
作者Author：Sky Yang
◆例题 Example
◆在线做 Do it by CTC
◆在线做 Do it by Penpa
