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)

int_list = list(map(int, input().split(' ')))

max_int = max(int_list)

cnt = 0
for i in range(3):
    if i < max_int:
        cnt_tmp = (max_int - int_list[i]) // 2
        int_list[i] += 2 * cnt_tmp
        cnt += cnt_tmp

min_int = min(int_list)
int_list2 = sorted([i - min_int for i in int_list])

if int_list2 == [0, 0, 0]:
    print(cnt)
elif int_list2 == [0, 0, 1]:
    print(cnt + 1)
else:
    print(cnt + 2)