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 Ruby (2.3.3) (judge verdict: Accepted)

array = gets.split(" ").map { |e| e.to_i }

guki = [0,0,0] #三つの偶奇を調べる
ki = 0
for i in 0..2 do
  if array[i]%2 == 1
    guki[i] = 1
    ki += 1
  end
end

count = 0

if ki == 1 #偶奇を揃える
  for i in 0..2 do
    if guki[i] == 0
      array[i] += 1
    end
  end
  count += 1
elsif ki == 2
  for i in 0..2 do
    if guki[i] == 1
      array[i] += 1
    end
  end
  count += 1
end

max = array.max #いちばん大きいのに合わせる
for i in 0..2 do
  if array[i] < max
    count += (max - array[i]) / 2
  end
end

puts count