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"
)

func main() {
	var A, B, C int
	fmt.Scan(&A, &B, &C)

	q := make([][]int, 0)

	patterns := [][]int{
		{2, 0, 0},
		{0, 2, 0},
		{0, 0, 2},
		{1, 1, 0},
		{0, 1, 1},
		{1, 0, 1},
	}

	q = append(q, []int{A, B, C, 0})

	d := make(map[[3]int]bool)
	ans := 0
	for len(q) > 0 {
		q0 := q[0]
		q = q[1:]
		a, b, c, x := q0[0], q0[1], q0[2], q0[3]

		k := [3]int{a, b, c}
		if d[k] {
			continue
		}
		d[k] = true

		if a == b && b == c {
			ans = x
			break
		}

		for _, p := range patterns {
			q = append(q, []int{a + p[0], b + p[1], c + p[2], x + 1})
		}
	}

	fmt.Println(ans)
}