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 (GCC 5.4.1) (judge verdict: Accepted)

#include<stdio.h>

int main(void)
{
  int a,b,c,ans=0,max,min,mid,abs=0;
  scanf("%d %d %d",&a,&b,&c);
  if(a > b)
    {
      if(c > a)
	{
	  max = c;
	  mid = a;
	  min = b;
	}
      else
	{
	  max = a;
	  if(b > c)
	    {
	      mid = b;
	      min = c;
	    }
	  else
	    {
	      mid = c;
	      min = b;
	    }
	}
    }
  else
    {
      if(c > b)
	{
	  max = c;
	  mid = b;
	  min = a;
	}
      else
	{
	  max = b;
	  if(a > c)
	    {
	      mid = a;
	      min = c;
	    }
	  else
	    {
	      mid = c;
	      min = a;
	    }
	}
    }
  abs = 2 * max - (mid + min);
  if(abs % 2 == 0)
    {
      ans = abs / 2;
    }
  else
    {
      ans = 1 + (abs+1) / 2;
    }
  printf("%d\n",ans);
  return 0;
}