main = getLine >>= mapM putStrLn . solve . (\[w, h, c] -> (map read [w, h], c)) . words

solve :: ([Int], String) -> [String]
solve ([w, h], c) = reverse $ f h where
    d = if c == "B" then "W" else "B"
    w2 = div w 2
    cd = concat $ zipWith (++) (replicate w2 c) (replicate w2 d)
    dc = reverse cd
    oddL = if odd w then cd ++ c else cd
    evenL = if odd w then dc ++ d else dc
    f 0 = []
    f i | odd i     = oddL : f (i - 1)
        | otherwise = evenL : f (i - 1)