规则Rules：
标准数独基础上，涂色格同时满足堡垒数独规则，以及额外区域数独规则。
Classic rules applied. Additionally, numbers in colored cells fits both the rules of Fortress and Extra Regions.
◆堡垒数独规则 Rules of Fortress
◆额外区域数独规则 Rules of Extra Regions
◆在线做Do it by CTC
◆在线做Do it by Penpa
