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 PyPy3 (2.4.0) (judge verdict: Accepted)

from sys import stdin


if __name__ == "__main__":
    _in = [_.rstrip() for _ in stdin.readlines()]
    A,B,C = list(map(int,_in[0].split(' ')))  # type:list(int)
    # vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
    cnt = 0
    if [A%2,B%2,C%2] in [[0,0,0],[1,1,1]]:
        pass
    else:
        if [A%2,B%2,C%2] in [[0,1,1],[1,0,0]]:
            B+=1
            C+=1
        elif [A%2,B%2,C%2] in [[1,0,1],[0,1,0]]:
            A+=1
            C+=1
        elif [A%2,B%2,C%2] in [[1,1,0],[0,0,1]]:
            A+=1
            B+=1
        cnt += 1
    arr = sorted([A,B,C])
    cnt += abs(arr[2]-arr[0])//2
    cnt += abs(arr[2]-arr[1])//2
    # ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    print(cnt)