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)

a = list(sorted(map(int, input().split())))
if (a[2] - a[0]) % 2 == 0 and (a[2] - a[1]) % 2 == 0:
    print((a[2] - a[0]) // 2 + (a[2] - a[1]) // 2)
elif (a[2] - a[0]) % 2 == 1 and (a[2] - a[1]) % 2 == 1:
    print((a[2] - a[0]) // 2 + (a[2] - a[1]) // 2 + 1)
else:
    if (a[2] - a[0]) % 2 == 1:
        a[0] += 2
        a[1] += 1
        a[2] += 1
    else:
        a[0] += 1
        a[1] += 2
        a[2] += 1
    a = sorted(a)
    if (a[2] - a[0]) % 2 == 0 and (a[2] - a[1]) % 2 == 0:
        print((a[2] - a[0]) // 2 + (a[2] - a[1]) // 2 + 2)
    elif (a[2] - a[0]) % 2 == 1 and (a[2] - a[1]) % 2 == 1:
        print((a[2] - a[0]) // 2 + (a[2] - a[1]) // 2 + 1 + 2)
    else:
        raise