Problem:
Score : 300 points

Problem Statement

You are given three integers A, B and C. Find the minimum number of operations required to make A, B and C all equal by repeatedly performing the following two kinds of operations in any order:

Choose two among A, B and C, then increase both by 1.

Choose one among A, B and C, then increase it by 2.

It can be proved that we can always make A, B and C all equal by repeatedly performing these operations.

Constraints

0 \leq A,B,C \leq 50

All values in input are integers.

Input

Input is given from Standard Input in the following format:

A B C

Output

Print the minimum number of operations required to make A, B and C all equal.

Sample Input 1

2 5 4

Sample Output 1

2

We can make A, B and C all equal by the following operations:

Increase A and C by 1. Now, A, B, C are 3, 5, 5, respectively.

Increase A by 2. Now, A, B, C are 5, 5, 5, respectively.

Sample Input 2

2 6 3

Sample Output 2

5

Sample Input 3

31 41 5

Sample Output 3

23

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

using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Linq;

class Program
{
    static void Main(string[] args)
    {
        // a=1番大きい数 b=２番目に大きい数 c=３番目に大きい数
        int a,b,c;
        int count=0;
        int[] str = Console.ReadLine().Split().Select(s => int.Parse(s)).ToArray();

        Array.Sort(str);
        a = str[2];
        b = str[1];
        c = str[0];

        while (b < a)
        {
            b++;
            c++;
            count++;
        }

        while (c < a)
        {
            c += 2;
            count++;

            if (a == b && b == c)
            {
                break;
            }

            if (a < c && b < c)
            {
                a++;
                b++;
                count++;
            }
        }

        Console.WriteLine(count);
    }
}