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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.Scanner;

public class Main {

    private static int A, B, C;

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        A = sc.nextInt();
        B = sc.nextInt();
        C = sc.nextInt();
        System.out.println(solve());
    }

    private static int solve() {
        int ans = 0;
        while(diff() >= 2 ) {
            plus2();
            ans++;
        }

        int cm = countMax();
        if( cm == 3 ) {
            return ans; // ok
        } else if( cm == 2 ) {
            return ans + 2; // 4 4 3 みたいなケース
        } else {
            return ans + 1; // 4 3 3 みたいなケース
        }
    }

    private static void show() {
        System.out.println( A + " " + B + " " + C );
    }

    private static int countMax() {
        int max = Math.max(Math.max(A, B), C);
        int cnt = 0;
        if( max == A ) cnt++;
        if( max == B ) cnt++;
        if( max == C ) cnt++;
        return cnt;
    }

    private static int diff() {
        int max = Math.max(Math.max(A, B), C);
        int min = Math.min(Math.min(A, B), C);
        return max - min;
    }

    private static void plus2() {
        int min = Math.min(Math.min(A, B), C);
        if( min == A ) {
            A = A+2;
        } else if( min == B ) {
            B = B+2;
        } else {
            C = C+2;
        }
    }
}