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 PHP7 (7.0.15) (judge verdict: Accepted)

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

$min = 10**10;
for($i = -2; $i <= 52;$i++){
    $sum = 0;
    foreach($array as $v){
        if($i > $v){
            if(($i - $v) % 2 == 1){
                $v--;
                $sum++;
            }
            $sum+=($i - $v)/2;
        }else{
            $sum+=$v-$i;
        }
    }
    $min = min($sum, $min);
}
echo $min;