import Data.Foldable
import Control.Applicative
import Data.Monoid
import Data.Foldable
import Prelude hiding (maximum,minimum)

instance Monoid a => Monoid (IO a) where
	mempty = return mempty
	mappend a b = mappend <$> a <*> b

getLines::Int->IO String
getLines 1 = getLine 
getLines n = getLine <> return "\n" <> (getLines$n-1)

main = do
	n<-read<$>getLine::IO Int
	k<-read<$>getLine::IO Int
	list<-fmap read<$>lines<$> getLines n::IO [Int]
	print$maximum list - minimum list