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())
ans = 0
while((A==B==C) == False):
    if A == B:
        if A > C:   # AとBが同じでかつCが最小
            C += 2
        else:
            A += 1
            B += 1

    elif B == C:
        if B > A:   # BとCが同じでかつAが最小
            A += 2
        else:
            B += 1
            C += 1

    elif C == A:
        if C > B:   # CとAが同じでかつBが最小
            B += 2
        else:
            C += 1
            A += 1
    else :           # 3つの変数がバラバラの時
        if A > B > C or A > C > B:
            B += 1
            C += 1
        elif B > A > C or B > C > A:
            A += 1
            C += 1
        else:
            A += 1
            B += 1
    ans += 1
print(ans)