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.Collections.Generic;
using System.Linq;
using System;
using static System.Console;

class Program
{
  static void Main() => new Program().solve();

  void solve()
  {
    var seq = ReadLine().Split(' ').Select(int.Parse).ToArray();
    var max = seq.Max();
    var seq2 = seq.Select(i => max - i);
    var cnt = seq2.Select(i => i / 2).Sum();
    switch(seq2.Select(i => i % 2).Sum())
      {
        case 1: cnt += 2;
          break;
        case 2: cnt += 1;
          break;
        default:
          break;
      }
    var ans = cnt;
    WriteLine(ans);
  }
}