import Control.Applicative ((<$>))
import Control.Monad
import Data.List

main :: IO ()
main = do
  solve <$> getl words >>= mapM_ putStrLn

solve :: [String] -> [String]
solve [sw, sh, sp] = take (read sh) $ cycle [l1, l2]
  where
    l1 = take (read sw) $ if sp == "B" then cycle "BW" else cycle "WB"
    l2 = take (read sw) $ if sp == "B" then cycle "WB" else cycle "BW"

getl :: (String -> a) -> IO a
getl f = f <$> getLine