import Data.List (unfoldr)

main = do
  getLine
  st <- getLine
  let [s,t] = words st
  let ans = compute s t
  putStrLn ans

-- compute s t = foldr (\(a,b) u -> a:b:u) [] $ zip s t
compute (s:ss) (t:ts) = s : t : compute ss ts
compute [] [] = []
{-
compute s t = unfoldr step (s,t)
  where
    step ([],_) = Nothing
    step (s:ss,ts) = Just (s, (ts,ss))
-}
