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 PHP (5.6.30) (judge verdict: Wrong Answer)

<?php
$input = fgets(STDIN);
$input = explode(" ",trim($input));
sort($input);

echo $input[0]."\n";
echo $input[1]."\n";
echo $input[2]."\n";
//実行回数
$try = 0;
if($input[0] == $input[1] && $input[1] == $input[2]) echo "$try"."\n";

for($i=0; $i<=1; $i++){
$increase = intval(($input[2] - $input[$i])/2);
$try += $increase;
$input[$i] += $increase*2;
}

if($input[0] == $input[1] && $input[1] == $input[2]){
  echo "$try"."\n";
}else{
  if($input[0] == $input[1]){
   echo strval($try+1)."\n";
  }else{
   echo strval($try+2)."\n";
  }
}