Description
The rule for placing a queen or a rock on the board is as follows:
1. Each row and column of the chessboard contains exactly 1 queen , and each diagonal also contains no more than 1 queen.
For example, a queen will threaten any other pieces on the red blocks in the following image
2. Each row and column of the chessboard contains no more than 1 rock.
That is, a rock will threaten any other pieces on the red blocks in the following image
Your have to put M queens and N rocks on an (M+N)x(M+N) chessboard in a way that no one threatens another.
Then, your task is to compute how many possible ways to put M queens and N rocks on the chessboard.
For instance, if M = 7 and N = 1, your answer should be 736 since there are 736 valid ways to arrange 7 queens and 1 rock on the chessboard.
Input
There are 2 integers in a line.
The first integer is M which means the number of queens that you need to put on the chessboard.
The second integer is N which means the number of rocks that you need to put on the chessboard.
Note that 1<=M+N<= 10
Output
An integer which represent the number of possible arrangements of M queens and N rocks.
You have to add '\n' at the end of output!