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: Wrong Answer)

#include<stdio.h>
#include<stdlib.h>

int compare_int(const void *a, const void *b)
{
    return *(int*)a - *(int*)b;
}

int kiriage( double x )
{
    return (int)( x < 0.0 ? x : x+0.9 );
}

int main(){
  int i,j,k=0;
  int A[3];
  scanf("%d %d %d",&A[0],&A[1],&A[2]);
  qsort(A,3,sizeof(int),compare_int);
  int diff[2];
  diff[0]=A[2]-A[0];
  diff[1]=A[2]-A[1];
  k += diff[1];
  diff[0] -=diff[1];
  k += kiriage((double)diff[0]/(double)2);
  printf("%d\n",k);
  return 0;
}