Junyi is an avid chess player. He would like to know how many ways it is possible to place rooks on an chessboard such that no rook are in an attacking position.
A rook can only move horizontally and vertically from its current position and two rooks are in an attacking position if one is on the path of the other.
The first line will contain two integers .
The number of ways to place rooks on an chessboard such that no rooks are in an attacking position.