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 (1.42.0) (judge verdict: Accepted)

use proconio::fastout;
use whiteread::parse_line;

#[fastout]
fn main() {
    let mut a: Vec<usize> = parse_line().unwrap();
    a.sort();

    let mut ret = 0;
    if (a[1] - a[0]) % 2 != 0 {
        ret += 1;
        a[0] += 1;
        a[2] += 1;
    }
    ret += (a[1] - a[0]) / 2;
    ret += a[2] - a[1];

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