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: Wrong Answer)

#include <iostream>
#include <string>
#include <algorithm> 
#include <cstdlib>
#include <map>
#include <queue>
#include <vector>
#include <utility>
#include <climits>
#include <numeric>
#define ll long long
#define INF INT_MAX 
using namespace std;
int main(){
	int a[3];
	cin >> a[0] >> a[1] >> a[2];
	int count=0;
	sort(a,a+3);
	reverse(a,a+3);
	if(a[0]==a[2]){
		cout << 0 << endl;
		return 0;
	}
	if(a[0]!=a[1]){
		while(1){
			a[1]++;
			a[2]++;
			count++;
			if(a[0]==a[1]){
				while(1){
					a[2]+=2;
					count++;
					if(a[2]==a[0]){
						cout << count << endl;
						return 0;
					}else if(a[2]>a[0]){
						cout << count + 1 << endl;
						return 0;
					}
				}
			}
		}
	}else{
		a[2]+=2;
		count++;
		if(a[2]==a[0]){
			cout << count << endl;
			return 0;
		}else{
			cout << count+1 << endl;
			return 0;
		}
	}
}