import Data.Maybe
import Control.Arrow
import Data.List

(.:) = (.) . (.)

eo :: [a] -> ([a], [a])
eo = f mask &&& f (tail mask)
  where f = catMaybes .: zipWith ($)
        mask = [Just, \_ -> Nothing] <> mask

rodds :: [[a]] -> [[a]]
rodds = concat . transpose . uncurry (<>) .
        (singleton *** singleton) .
        second (map reverse) . eo

main = interact $ unwords . rodds . words