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 <bits/stdc++.h>
using namespace std;

int main()
{
    int A, B, C;
    cin >> A >> B >> C;
    int ans = 0;
    if (A % 2 == B % 2 && B % 2 != C % 2)
    {
        A++;
        B++;
        ans++;
    }
    if (B % 2 == C % 2 && C % 2 != A % 2)
    {
        B++;
        C++;
        ans++;
    }
    if (C % 2 == A % 2 && A % 2 != B % 2)
    {
        C++;
        A++;
        ans++;
    }
    int x[3] = {A, B, C};
    sort(x, x + 3);
    ans += (2 * x[2] - x[0] - x[1]) / 2;
    cout << ans << endl;
}