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)

a,b,c=gets.split(" ").map(&:to_i)
m1 = [a,b,c].max
m3 = [a,b,c].min
m2 = a + b + c - m1 - m3
count=0
while m2<m1
  m2+=1
  m3+=1
  count+=1
end
if (m2-m3) % 2 == 1
  m1+=1
  m2+=1
  count+=1
end
t = (m2-m3)/2
t.times do
  m3+=2
  count+=1
end
puts count