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)

#import collections
#aa = collections.Counter(a) # list to list
#from itertools import combinations # (string,3) 3回

mod = 10**9 + 7

def readInts():
  return list(map(int,input().split()))
def main():
    a,b,c = readInts()
    if (max(a,b,c)*3 - a - b - c) % 2 == 0:# 3 4 5  5 * 3 = 15 15 - 12 = 3
        print((max(a,b,c)*3 - a - b - c)//2)
    else:
        print(((max(a,b,c)*3 - a - b - c) //2)+2) # 3 4 5 (1+2) 
if __name__ == '__main__':
  main()