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 Fortran (gfortran v4.8.4) (judge verdict: Accepted)

read*,i,j,k
if(j<i)then
n=i;i=j;j=n
endif
if(k<j)then
n=j;j=k;k=n
endif
if(j<i)then
n=i;i=j;j=n
endif
n=(k-i)/2+(k-j)/2;i=i+2*((k-i)/2);j=j+2*((k-j)/2);k=i+j-k-k
if(k==-1)then
n=n+2
else if(k==-2)then
n=n+1
endif
print"(i0)",n
end