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<iostream>
#define swp(a,b) {int t=a;a=b;b=t;}
using namespace std;
int main(){
  int a, b, c, k=0;
  cin >> a >> b >> c;
  while(!(a==b&&b==c)){
    if(a<b)swp(a,b);
    if(a<c)swp(a,c);
    if(b<c)swp(b,c);
    while(a>b && a>c){b++;c++;k++;}
    while(a>c){c+=2;k++;}
  }
  cout << k;
  return 0;
}