import Data.List.Split
import Data.List

main = do
    a <- getContents
    let aa = head $ splitOn "\n" a
    putStr $ getOddStr "" aa 1

getOddStr :: String -> String -> Int -> String
getOddStr a [] _ = a
getOddStr r (s: ss) i = if even i then getOddStr r ss (i + 1) else getOddStr (r++[s] ) ss (i + 1)
