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.Generic;
using System.Linq;
using static System.Console;
using System.Runtime.CompilerServices;
using static MyUtil;

class MyUtil
{
    public static int[] ReadIntArray()
    {
	return ReadLine().Split().Select(x => int.Parse(x)).ToArray();
    }
}

class Program
{
    public static void Main()
    {
	int[] x = ReadIntArray();
	Array.Sort(x);
	WriteLine(Solve(x));
    }

    static bool isEven(int x)
    {
	return ((x&1) == 0);
    }
    
    static int Solve(int[] x)
    {
	int d0 = x[2]-x[0];
	int d1 = x[2]-x[1];

	if (isEven(d0) && isEven(d1)) // even, even
	{
	    return d0/2 + d1/2;
	}
	else if (isEven(d0)) // even, odd
	{
	    x[0] += 1;
	    x[2] += 1;
	}
	else if (isEven(d1)) // odd, even
	{
	    x[1] += 1;
	    x[2] += 1;
	}
	else // odd, odd
	{
	    x[0] += 1;
	    x[1] += 1;
	}
	return 1 + Solve(x);
    }
}