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() {
	vector<int> a(3);
  	cin >> a[0] >> a[1] >> a[2];
  	sort(a.begin(), a.end());
  	a[1] -=a[0];a[2] -=a[0];a[0] = 0;
  	if(a[1] %2 == 0 && a[2] % 2 == 0)
      	cout << (a[2] - a[1]) /2 + a[2] /2 << endl;
    else if(a[1] % 2 == 0 && a[2] % 2 == 1)
      	cout << 1+(a[2]-1)/2+(a[2]-a[1]-1)/2 <<endl;
  	else if(a[1] % 2 == 1 && a[2] % 2 == 0)
      	cout << 1 + a[2]/2+(a[2]-a[1] +1)/2 << endl;
  	else
      	cout << 1 + (a[2]-a[1])/2+(a[2]+1)/2 << endl;
}