Introduction - If you have any usage issues, please Google them yourself
chessboard coverage : two in a k-th power of 2 multiplied by the k-th power grid consisting of a chessboard, and a box with the other box, the box said to a special box and said the chessboard for a special chessboard. On the chessboard coverage, in four different forms of L-type domino coverage to the special chessboard except in special box outside the box at all.