规则Rules：
标准数独基础上，提示表示其相邻两格乘积的十位上的数值。
Classic rules applied. Additionally, if a digit is marked between two cells, then it's same to the tens place of the product of the two digits in the grids.
◆例题 Example
◆在线涂鸦 Draw it Online
◆在线做 Do it by CTC
◆在线做 Do it by Penpa
