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>

int main()
{
	using namespace std;
	int a,b,c;
	cin>>a>>b>>c;
	int counter=0;
	int t;
	if(a>b)
	{
		t=a;a=b;b=t;
	}
	if(a>c)
	{
		t=a;a=c;c=t;
	}
	if(b>c)
	{
		t=b;b=c;c=t;
	}
	int minus_=b-a;
	if(minus_%2==0)
	{
		counter+=minus_/2;
		counter+=c-b;
	}
	else
	{
		counter++;
		a+=1;
		c+=1;
		minus_=b-a;
		counter+=minus_/2;
		counter+=c-b;
	}
	cout<<counter<<endl;
	return 0;
}