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() {
	var a, b, c int
	fmt.Scan(&a)
	fmt.Scan(&b)
	fmt.Scan(&c)

	count := 0
	d := []int{a, b, c}
	sort.Ints(d)
	if 2 <= (d[1] - d[0]) {
		cnt := (d[1] - d[0]) / 2
		count = count + cnt
		d[0] = d[0] + cnt*2
	}

	sort.Ints(d)
	if 0 < (d[2] - d[1]) {
		cnt := d[2] - d[1]
		count = count + cnt
		d[0] = d[0] + cnt
		d[1] = d[1] + cnt
	}

	s := make([][]int, 0)
	s = append(s, d)

	for {
		isBreak := false
		for _, x := range s {
			if x[0] == x[1] && x[1] == x[2] {
				isBreak = true
				break
			}
		}
		if isBreak {
			break
		}

		t := make([][]int, 0)
		for _, x := range s {
			t = append(t, []int{x[0] + 1, x[1] + 1, x[2]})
			t = append(t, []int{x[0] + 1, x[1], x[2] + 1})
			t = append(t, []int{x[0], x[1] + 1, x[2] + 1})
			t = append(t, []int{x[0] + 2, x[1], x[2]})
			t = append(t, []int{x[0], x[1] + 2, x[2]})
			t = append(t, []int{x[0], x[1], x[2] + 2})
		}
		for _, x := range t {
			s = append(s, x)
		}

		count++
	}

	fmt.Printf("%d\n", count)
}