Problem:
Score : 300 points

Problem Statement

You are given an integer sequence of length n, a_1, ..., a_n.
Let us consider performing the following n operations on an empty sequence b.

The i-th operation is as follows:

Append a_i to the end of b.

Reverse the order of the elements in b.

Find the sequence b obtained after these n operations.

Constraints

1 \leq n \leq 2\times 10^5

0 \leq a_i \leq 10^9

n and a_i are integers.

Input

Input is given from Standard Input in the following format:

n
a_1 a_2 ... a_n

Output

Print n integers in a line with spaces in between.
The i-th integer should be b_i.

Sample Input 1

4
1 2 3 4

Sample Output 1

4 2 1 3

After step 1 of the first operation, b becomes: 1.

After step 2 of the first operation, b becomes: 1.

After step 1 of the second operation, b becomes: 1, 2.

After step 2 of the second operation, b becomes: 2, 1.

After step 1 of the third operation, b becomes: 2, 1, 3.

After step 2 of the third operation, b becomes: 3, 1, 2.

After step 1 of the fourth operation, b becomes: 3, 1, 2, 4.

After step 2 of the fourth operation, b becomes: 4, 2, 1, 3.

Thus, the answer is 4 2 1 3.

Sample Input 2

3
1 2 3

Sample Output 2

3 1 2

As shown above in Sample Output 1, b becomes 3, 1, 2 after step 2 of the third operation. Thus, the answer is 3 1 2.

Sample Input 3

1
1000000000

Sample Output 3

1000000000

Sample Input 4

6
0 6 7 6 7 0

Sample Output 4

0 6 6 0 7 7

Solution in Haskell (GHC 7.10.3) (judge verdict: Accepted)

import Control.Monad
import Control.Monad.Primitive (PrimState)
import qualified Data.Vector as V
import qualified Data.Vector.Mutable as MV
import qualified Data.ByteString.Char8 as B
import Data.Maybe (fromJust)
import Data.IORef

main :: IO ()
main = do
    n <- fst . fromJust . B.readInt <$> B.getLine
    as <- V.fromList . B.words <$> B.getLine
    mv <- MV.unsafeNew (n + 1) :: IO (MV.MVector (PrimState IO) B.ByteString)
    l <- newIORef (n `div` 2)
    r <- newIORef (n `div` 2 + 1)
    forM_ [0..(n - 1)] $ \i ->
        if i `mod` 2 == (n - 1) `mod` 2
            then do
                m <- readIORef l
                MV.unsafeWrite mv m (as V.! i)
                modifyIORef l pred
            else do
                m <- readIORef r
                MV.unsafeWrite mv m (as V.! i)
                modifyIORef r succ
    j <- readIORef l
    v <- V.unsafeFreeze $ MV.slice (j + 1) n mv
    B.putStrLn $ B.unwords $ V.toList v