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 <bits/stdc++.h>
#define rep0(i,n) for (int i = 0; i < (n); ++i)
#define rep1(i,n) for (int i = 1; i < (n); ++i)
#define REP(i,a,b) for (int i = a; i < (b); ++i)
#define mREP(i,a,b) for (int i = a; i > (b); --i)
#define all(x) (x).begin(),(x).end()
const int INF = 1000000007;
typedef long long ll;
using namespace std;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
ll gcd(ll a, ll b) { return b ? gcd(b, a%b) : a; }

int main(){
  vector<int>a(3);
  rep0(i,3)cin >> a[i];
  sort(a.begin(),a.end());
  int ans = 0;
  ans = a[2] - a[1];
  a[0] += ans;
  ans += (a[2] - a[0]) / 2;
  cout << ans << endl;
  return 0;
}