import Data.Bits
import Data.List

successor :: Int -> [Bool] -> Bool
successor r bs = testBit r . sum $
                 zipWith (shiftL . fromEnum) (reverse bs) [0..]

nextRow :: Int -> [Bool] -> [Bool]
nextRow r cs = map (successor r) . take (length cs) . transpose .
               take 3 . iterate (drop 1) $ [head cs] ++ cs ++ [last cs]

displayRow :: [Bool] -> String
displayRow = intersperse ' ' . map (\b -> if b then 'X' else ' ')

cells :: Int -> Int -> [String]
cells r h = map displayRow . take (h + 1) . iterate (nextRow r) $
            replicate h False ++ [True] ++ replicate h False

main :: IO ()
main = mapM_ putStrLn $ cells 82 15