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 Python (3.4.3) (judge verdict: Accepted)

def main():
  t = input().split(" ")
  A, B, C = int(t[0]), int(t[1]), int(t[2])
  M = max(A, B, C)
  n = (M-A)//2 + (M-B)//2 + (M-C)//2
  r = (M-A)%2 + (M-B)%2 + (M-C)%2
  if r == 1:
    n += 2
  elif r == 2:
    n += 1
  print(n)
main()