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.

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.

Constraints

• $0 \leq A,B,C \leq 50$
• All values in input are integers.

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

见题面 Input 部分

见题面 Output 部分