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 Rust (1.15.1) (judge verdict: Accepted)

fn main() {
    let mut buf = String::new();
    std::io::stdin().read_line(&mut buf).ok();
    let v: Vec<u32> = buf.split_whitespace().map(|x| x.parse().unwrap()).collect();
    let v_max = v.iter().fold(0, |max, &x| std::cmp::max(max, x));

    let mut ans = 0;
    let mut rest = 0;
    for &x in v.iter() {
        ans += (v_max - x) / 2;
        rest += (v_max - x) % 2;
    }
    ans += match rest {
        2 => 1,
        1 => 2,
        _ => 0,
    };

    println!("{}", ans);
}