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;
#define MOD 1000000007
#define rep(i, n) for(int i = 0; i < (int)(n); i++)
#define rep1(i, n) for(int i = 1; i <= (int)(n); i++)
#define showmap(is, js, x) {rep(i, is){rep(j, js){cout << x[i][j] << " ";}cout << endl;}}
#define show(x) {for(auto i: x){cout << i << " ";} cout<<endl;}
#define showm(m) {for(auto i: m){cout << m.x << " ";} cout<<endl;}
typedef long long ll;
typedef pair<int, int> P;
typedef pair<ll, ll> llP;
ll gcd(int x, int y){ return y?gcd(y, x%y):x;}
ll lcm(ll x, ll y){ return (x*y)/gcd(x,y);}


int main()
{
    int a, b, c;
    cin >> a >> b >> c;

    int max_abc = max(max(a, b), c);

    int diff = max_abc - a;
    diff += max_abc - b;
    diff += max_abc - c;

    if (diff%2==0){
        cout << diff/2 << endl;
    } else {
        cout << (diff+3)/2 << endl;
    }
}