import Data.List (sortBy)

main :: IO ()
main = do
    (_:ps) <- getParams
    print . solve $ sortDesc ps

getParams :: IO [Int]
getParams = map read . words <$> getContents

solve :: [Int] -> Int
solve (p:ps) = p `div` 2 + sum ps

sortDesc :: Ord a => [a] -> [a]
sortDesc = sortBy (flip compare)
