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++ (GCC 5.4.1) (judge verdict: Accepted)

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

#define mp make_pair
#define pb push_back
#define st first
#define nd second

typedef long long ll;
typedef pair < ll , ll > pp;
const int mod = 1e9 + 7;
const int N   = 2e5 + 5;

int a[5],t;

signed main(){
    cin >> a[1] >> a[2] >> a[3];
    sort(a+1 , a+3+1);
    t = a[3]-a[2] + a[3]-a[1];
    cout << t/2 + (t&1 ? 2 : 0);
    return 0;
}