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 (Clang 3.8.0) (judge verdict: Accepted)

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <math.h>
#include <numeric>
#include <sstream>
#include <set>
#include <map>
#define LLMAX 9223372036854775807

using namespace std;
using ll = long long;

int main() {
	vector<ll> argA(3);
	for (ll i = 0; i < 3; ++i) {
		cin >> argA.at(i);
	}

	sort(argA.begin(), argA.end());

	ll firstOp = argA.at(2) - argA.at(1);
	ll diff = argA.at(2) - argA.at(0) - firstOp;
	ll secondOp = diff % 2 == 0 ? diff / 2 : diff / 2 + 2;

	cout << firstOp + secondOp << endl;
}