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)

macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let mut s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};

    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };

    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };

    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };

    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };

    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}

fn min (a: &i64, b: &i64)-> i64{
    if *a <= 0i64 {*b}
    else if *b <= 0i64  {*a}
    else if *a < *b {*a}
    else {*b}
}

fn abs (a: &i64, b: &i64) -> i64{
    if *a - *b <= 0 {*b - *a} else {*a - *b}
}

use std::collections::VecDeque;
fn main(){
    input!{
        base: [usize; 3],
    }
    let mut count = 0;
    let mut a = base.clone();
    if a[0] % 2 == a[1] % 2 && a[0] % 2 != a[2] % 2{
        a[0] += 1;
        a[1] += 1;
        count += 1;
    }
    else if a[0] % 2 == a[2] % 2 && a[1] % 2 != a[2] % 2{
        a[0] += 1;
        a[2] += 1;
        count += 1;
    }
    else if a[2] % 2 == a[1] % 2 && a[0] % 2 != a[2] % 2{
        a[2] += 1;
        a[1] += 1;
        count += 1;
    }
    a.sort();
    while a[0] < a[2] {
        a[0] += 2;
        count += 1;
    }
    while a[1] < a[2] {
        a[1] += 2;
        count += 1;
    }
    println!("{}", count);
}