规则Rules：
标准数独基础上，提示A的周围数字中，任意两个数字的差不是A。
Classic rules applied. Additionally, each two numbers around clue A, their difference cannot be A.
◆例题 Examples
◆在线涂鸦 Draw it Online
◆在线做 Do it by CTC
◆在线做 Do it by Penpa
