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 <string>
#include <vector>
#include <algorithm>
#include <math.h>

typedef long long int ll;

#define FOR(i,n,m) for(ll i=(ll)(m);i<(ll)(n);++i)
#define REP(i,n) FOR(i,n,0)
#define IREP(i,n) for(ll i=(ll)(n);i>=0;--i)

const ll MOD = 1000000007;

using namespace std;

int main()
{
	int A, B, C;
	cin >> A >> B >> C;
	int max = std::max(A, std::max(B, C));
	int min = std::min(A, std::min(B, C));
	int mid = A + B + C - max - min;

	int ans = max - mid;
	ans += (mid - min) / 2;
	if ((mid - min) % 2 == 1)
	{
		ans += 2;
	}
	cout << ans << endl;
	return 0;
}