规则Rules：
标准数独基础上，每个灰色区域中，所有奇数的和等于所有偶数的和。
Classic rules applied. In each grey zones, the sum of all the odd numbers, equals to the sum of all the even numbers.
◆在线涂鸦 Draw it Online
◆在线做 Do it by CTC
◆在线做 Do it by Penpa
