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 Go (1.6) (judge verdict: Accepted)

package main

import (
	"fmt"
	"sort"
)

func main() {
	x := make([]int, 3)
	for i := 0; i < 3; i++ {
		fmt.Scan(&x[i])
	}

	sort.Sort(sort.IntSlice(x))

	if (3*x[2]-mySum(x))%2 == 0 {
		fmt.Println((3*x[2] - mySum(x)) / 2)
	} else {
		fmt.Println((3*(1+x[2]) - mySum(x)) / 2)
	}
}

func mySum(x []int) int {
	sum := 0
	for i := 0; i < len(x); i++ {
		sum += x[i]
	}
	return sum
}