Problem:
Score : 100 points

Problem Statement

You have three tasks, all of which need to be completed.

First, you can complete any one task at cost 0.

Then, just after completing the i-th task, you can complete the j-th task at cost |A_j - A_i|.

Here, |x| denotes the absolute value of x.

Find the minimum total cost required to complete all the task.

Constraints

All values in input are integers.

1 \leq A_1, A_2, A_3 \leq 100

Input

Input is given from Standard Input in the following format:

A_1 A_2 A_3

Output

Print the minimum total cost required to complete all the task.

Sample Input 1

1 6 3

Sample Output 1

5

When the tasks are completed in the following order, the total cost will be 5, which is the minimum:

Complete the first task at cost 0.

Complete the third task at cost 2.

Complete the second task at cost 3.

Sample Input 2

11 5 5

Sample Output 2

6

Sample Input 3

100 100 100

Sample Output 3

0

Solution in Haskell (GHC 7.10.3) (judge verdict: Accepted)

module Main (main) where

import qualified Data.ByteString.Char8 as C8
import Data.Bool
import Data.Maybe
import Data.List

main :: IO ()
main = do
  [a1,a2,a3] <- readInts
  print . showAnswer $ solve (a1,a2,a3)

type Input  = (Int, Int, Int)
type Output = Int

solve :: Input -> Output
solve (a1,a2,a3) = sum (zipWith (-) xs (tail xs))
  where
    xs = sortOn negate [a1,a2,a3]

showAnswer :: Output -> Answer
showAnswer = Number

-- utils
readInts :: IO [Int]
readInts = map (fst . fromJust . C8.readInt) . C8.words <$> C8.getLine

data Answer
  = YesNo Bool
  | YESNO Bool
  | AB Bool
  | Number Int
  | String String
  | Compare Ordering
  | Compare2 Ordering

instance Show Answer where
  show (YesNo b)    = bool "No" "Yes" b
  show (YESNO b)    = bool "NO" "YES" b
  show (AB b)       = bool "B"  "A" b
  show (Number i)   = show i
  show (String s)   = s
  show (Compare o)  = ordering "<" "=" ">" o
  show (Compare2 o) = ordering "Right" "Balanced" "Left" o

ordering :: a -> a -> a -> Ordering -> a
ordering lt eq gt o = case o of
  LT -> lt
  EQ -> eq
  GT -> gt