module Main where

import qualified Data.ByteString.Char8         as BS
import           Data.Char
import           Data.String
import           Data.List
import           Data.Maybe
import           Control.Monad

main :: IO ()
main = do
  [n, k] <- map (fst . fromJust . BS.readInt) . BS.words <$> BS.getLine
  an     <- map (fst . fromJust . BS.readInt) . BS.words <$> BS.getLine
  let maxi = maximum . map sum . filter (\l -> k >= length l) $ subsequences an
  print maxi