import qualified Data.ByteString.Char8 as B
import           Control.Monad
import qualified Data.Vector.Unboxed as VU
import           Data.Maybe
import           Data.List

readInt = fst . fromJust . B.readInteger

getInt = readInt <$> B.getLine
getIntN n = map readInt <$> replicateM (fromIntegral n) B.getLine

main :: IO ()
main = do
    n <- getInt
    k <- getInt
    ns <- getIntN n
    print $ solve ns

solve :: [Integer] -> Integer
solve ns = (last ns') - (head ns')
    where ns' = sort ns