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 C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <iostream>
#include <algorithm>
using namespace std;

int main()
{
	int a, b, c;
	cin >> a >> b >> c;
	if(a > b) swap(a, b);
	if(a > c) swap(a, c);
	if(b > c) swap(b, c);
	int ans = 0;
	ans += (c - a) / 2;
	a += ((c - a) / 2 * 2);
	ans += (c - b) / 2;
	a += ((c - b) / 2 * 2);
	int t = (c - b) + (c - a);
	cout << ans + (t == 0 ? 0 : 3 - t) << endl;
	return 0;
}