规则Rules：
标准数独基础上，提示表示这一方向上有多少种数字。
Classic rules applied. Additionally, clue shows how many kinds of number on it's direction.
作者Author：GGDumplings
◆例题 Examples
◆在线涂鸦Draw it Online
◆在线做Do it by CTC
◆在线做 Do it by Penpa
