-- where twoTiles, etc, give the total number of tiles used if each corner has
-- a block of tiles two, or three, or ... tiles deep.

-- You ... COULD generalize the above equations if you want...

ntiles :: Int -> Int -> Int
ntiles = (8 *) <<- (*)
ntiles :: Int -> Int -> Int
ntiles = (8 *) <<- (*)
ntiles = (8 *) <<- (*)