import Data.List
import qualified Data.ByteString.Char8 as B

main :: IO ()
main = getLine >> breads >>= print . solve

solve :: [Int] -> Int 
solve xs = last ys - head ys
    where
        ys = sort xs

breads :: IO [Int]
breads = unfoldr uff <$> B.getLine
    where
        uff b = check <$> B.readInt b
        check (a, b)
            | B.null b = (a, b)
            | otherwise = (a, B.tail b)