规则Rules：
① 异形规则Rules of Variant Classic:
填入1~9，使得每行、列、宫内数字不重复。
Write1~9, make numbers no repeated in each Row/Column/Box.
② 摩天和规则Rules of Skyscrapers Sum:
外提示表示从这一方向上观察，大数字能遮住小数字时，可以看见的所有数字的和。
The outside number shows the sum of all the numbers which can be seen in this direction, when larger number will hide the lower ones.
