(defvar W)
(defvar H)
(defvar C)
(defvar temp)

(setq temp (read-from-string (concatenate 'string "(" (read-line) ")")))
(setq W (nth 0 temp))
(setq H (nth 1 temp))
(setq C (nth 2 temp))

(setq C (if (eq C 'B) #\B #\W))

(defvar sentou)
(loop for i from 1 to H do
 	(setq sentou C )
 	(loop for j from 1 to W do
	 	(format 't "~c" C)
		(setq C (if (eq C #\B ) #\W #\B ))
	)
	(setq C (if (eq sentou #\B ) #\W #\B ))
	(format 't "~%")
)