样例输入 #1
样例输出 #1
样例说明 1
We can arrange the first three blocks in any order, except for or . The last block has to be at the bottom.
样例输入 #2
样例输出 #2
样例说明 2
We are not allowed to put a cube of size onto a cube of size .
There are six ways to order the cubes of size , and six ways to order the cubes of size .
