柠檬Lemon

标准数独基础上，柠檬中心的两个数字组成了一个从左到右、从上到下的两位数，它等于柠檬线条上所有数字的和。

Classic rules applied. Additionally, the two numbers in the center of the lemon forms a 2-digit number (from left to right, up to down), and it equals to the sum of all the numbers on the lemon lines.

赛事频率 极低

世界数独锦标赛题型（2018年左右）。