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 (
	"bufio"
	"fmt"
	"io"
	"log"
	"os"

	"sort"
	"strconv"
)

func solve(in io.Reader, out io.Writer) error {
	sc := bufio.NewScanner(in)
	sc.Split(bufio.ScanWords)

	a, b, c := nextInt(sc), nextInt(sc), nextInt(sc)
	l := []int{a, b, c}
	sort.Ints(l)

	d0 := l[2] - l[0]
	d1 := l[2] - l[1]

	if d0%2 == d1%2 {
		fmt.Fprintln(out, d0/2+d1/2+d0%2)
	} else {
		fmt.Fprintln(out, d0/2+d1/2+2)
	}

	return nil
}

func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return i
}

func main() {
	err := solve(os.Stdin, os.Stdout)
	if err != nil {
		log.Fatal(err)
	}
}