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, B, C = map(int, input().split())

m = max(A, B, C)
num1 = min(A, B, C)
num2 = min(max(A, B), C) if A == num1 or B == num1 else min(max(B, C), A)
count = 0

if (m - num1) % 2 == (m - num2) % 2:
    if (m - num1) % 2 == 0:
        count += (m - num1) / 2
        count += (m - num2) / 2
    else:
        count += (m - num1) // 2
        count += (m - num2) // 2
        count += 1
    print(int(count))

else:
    if (m - num1) % 2 == 0:
        count += (m - num1) / 2
        count += (m - num2) // 2
        count += 2
    else:
        count += (m - num2) / 2
        count += (m - num1) // 2
        count += 2
    print(int(count))