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)

nums = list(map(int, input().split()))

odd = 0
even = 0

for n in nums:
    if n % 2 == 0:
        even += 1
    else:
        odd += 1

ans = 0

if odd != 3 and even != 3:
    for i in range(3):
        if odd > even and nums[i] % 2 == 1:
            nums[i] += 1
        elif even > odd and nums[i] % 2 == 0:
            nums[i] += 1
    ans += 1

m = max(nums)
for n in nums:
    ans += (m - n) // 2

print(ans)