import Data.List (sort)

median :: (Fractional a, Ord a) => [a] -> a
median xs = if odd l then ys !! m else (ys !! m + ys !! (m - 1)) / 2
    where
        ys = sort xs
        l = length xs
        m = div l 2

main :: IO ()
main = getLine >> getLine >>= print . median . map read . words