import Control.Applicative
import Control.Monad
import Data.List

f w h c = take h $ (if c=="B" then id else tail) checker
  where
    checker = take w bwstr : take w (tail bwstr) : checker
    bwstr = 'B':'W':bwstr

main = words <$> getLine >>= \[w, h, c] -> mapM_ putStrLn $ f (read w) (read h) c