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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;

namespace AtCoder
{
    class Program
    {
        static void Main(string[] args)
        {
            //[summary];A - Task Scheduling Problem
            var line = ReadLine();
            var combis = AllCombinations<int>(line, 3, true).ToList();
            int min = int.MaxValue;

            foreach(var tasks in combis)
            {
                int cost = CalcTotalCost(tasks);

                if (cost < min)
                {
                    min = cost;
                }
            }

            Console.WriteLine(min);
        }

        static int CalcTotalCost(List<int> tasks)
        {
            int total = Math.Abs(tasks[1] - tasks[0]);
            total += Math.Abs(tasks[2] - tasks[1]);

            return total;
        }

        static IEnumerable<List<T>> AllCombinations<T>(List<T> source, int n,
                                                       bool isAllowDupication = false)
        {
            //[summary]異なる要素から、n個を選ぶ組み合わせを列挙する
            //"isAllowDupication"を"true"にすると、重複を許可する
            //(重複を許可して、nを要素数と同じにすると、順列を列挙する)

            if (n == 1)
            {
                foreach (var s in source)
                {
                    yield return new List<T> { s };
                }

                yield break;
            }
            else
            {
                for (int i = 0; i < source.Count; i++)
                {
                    List<T> clone;

                    if (isAllowDupication)
                    {
                        //重複を許可する場合は、その要素のみを削除
                        clone = new List<T>(source);
                        clone.RemoveAt(i);
                    }
                    else
                    {
                        //重複を許可しない場合は、自分よりも前の要素はすべて削除
                        clone = new List<T>(source.Skip(i + 1));
                    }

                    //再帰処理
                    var items = AllCombinations(clone, n - 1, isAllowDupication);

                    foreach (var item in items)
                    {
                        item.Insert(0, source[i]);
                        yield return item;
                    }
                }
            }
        }

        static List<int> ReadLine()
        {
            var line = Console.ReadLine();
            var array = line.Split(' ');

            return array.Select(x => int.Parse(x)).ToList();
        }
    }
}