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)

// finish date: 2018/03/25

#include <bits/stdc++.h>

using namespace std;

#define FOR(i, a, b) for(int (i)=a;(i)<(b);(i)++)
#define rep(i, n)  FOR(i,0,n)
#define ll long long
#define vi vector<int>
#define vvi vector<vector<int>>
#define vvvi vector<vector<vector<int>>>
#define vl vector<ll>
#define vvl vector<vector<ll>>
#define vd vector<double>
#define vvd vector<vector<double>>
#define vb vector<bool>
#define vvb vector<vector<bool>>
#define vs vector<string>
#define vc vector<char>
#define vvc vector<vector<char>>
#define bigmod 1000000007
#define INF 1050000000
#define pii pair<int,int>


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

    return 0;
}