标准数独基础上，提示表示了框内数字之和的奇偶性。
Classic rules applied. Additionally, O and E clues show the parity of the sum of numbers in cages.
标准数独基础上，数字从圆球开始沿着线条逐渐增大。
Classic rules applied. Additionally, numbers increasing from bulb on each thermometer.
标准数独基础上，提示表示相邻两格的和或者差。
Classic rules applied. Additionally, the clue indicates the sum or difference of the two cells adjacent to it.
标准数独基础上，每条线条上的数字之和等于圆圈里的数字。
Classic rules applied. Additionally, the sum of numbers on each line is the numbers in circle.
标准数独基础上，对于在杠杆上的任一数字而言，其与该杠杆中心的距离（中心格的相邻格算作距离1），乘以其本身的大小称为其力矩。对于每一个杠杆，其两侧的所有力矩之和相等。
标准数独基础上，每个虚线框内数字不重复，角标是框内数字之和。本题中，角标里的数字使用了未知数进行表示，相同的字母代表相同的数字，不同的字母也有可能代表相同的数字。
Classic rules applied. Additionally, numbers cannot repeat in each cage, clue is the sum of the numbers. Specially in this puzzle, clues are instead by unknown number X and Y. Same letter means same numbers, different letters may mean same or different numbers.
标准数独基础上，圆圈格子填奇数，方块格子填偶数。
Classic rules applied. Additionally, circle cells contain odd numbers, square cells contain even numbers.
标准数独基础上，每条线条上的数字之和等于圆圈里的数字。
Classic rules applied. Additionally, the sum of numbers on each line is the numbers in circle.
标准数独基础上，每条对角线上数字也不重复。
Classic rules applied. Additionally, numbers cannot repeat on each diagonal.
填入1~4，使得每行、列、宫内数字都是1~4不重复，并且余下两个空格（不填入任何字符）。外提示是这一方向上的第一个数字。
Write1~4, make each Row/Column/Box contains a group of 1~4, and two blank cells with nothing inside. The outside clue is the first number on this direction.
