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 <map>
#include <cmath>
#include <algorithm>
#include <functional>
#include <stack>
#include <numeric>
typedef long long ll;
using namespace std;
const int MOD = (int)1e9 + 7;
const ll INF = (ll)1e18 + 7;
//#define int long long
#define all(vec) vec.begin(), vec.end()

int dx[4] = {0, 1, 0, -1};
int dy[4] = {1, 0, -1, 0};

signed main()
{
	cin.tie(0);
	ios::sync_with_stdio(false);

	int A, B, C;
	cin >> A >> B >> C;
	int sum = A + B + C;
	int m = max(max(A, B), C);
	int ans;
	int maxx;
	if ((m * 3) % 2 == sum % 2)
	{
		maxx = m;
	}
	else
	{
		maxx = m + 1;
	}

	cout << (maxx * 3 - sum) / 2 << endl;

	return 0;
}