Problem:
Score : 200 points

Problem Statement

AtCoDeer the deer found two rectangles lying on the table, each with height 1 and width W.
If we consider the surface of the desk as a two-dimensional plane, the first rectangle covers the vertical range of [0,1] and the horizontal range of [a,a+W], and the second rectangle covers the vertical range of [1,2] and the horizontal range of [b,b+W], as shown in the following figure:

AtCoDeer will move the second rectangle horizontally so that it connects with the first rectangle.
Find the minimum distance it needs to be moved.

Constraints

All input values are integers.

1≤W≤10^5

1≤a,b≤10^5

Input

The input is given from Standard Input in the following format:

W a b

Output

Print the minimum distance the second rectangle needs to be moved.

Sample Input 1

3 2 6

Sample Output 1

1

This input corresponds to the figure in the statement. In this case, the second rectangle should be moved to the left by a distance of 1.

Sample Input 2

3 1 3

Sample Output 2

0

The rectangles are already connected, and thus no move is needed.

Sample Input 3

5 10 1

Sample Output 3

4

Solution in Rust (1.42.0) (judge verdict: Accepted)

use std::io;
use std::io::{stdin, Read};
use std::process::exit;
use std::cmp::min;

fn main() {

    let mut scan = stdin();
    let mut line = String::new();

    let _ = scan.read_line(&mut line);
    let inputs: Vec<&str> = line.split_whitespace().collect();

    let w: i32 = inputs[0].parse().unwrap();
    let a: i32 = inputs[1].parse().unwrap();
    let b: i32 = inputs[2].parse().unwrap();

    // println!("w:{} a:{} b:{}", w,a,b);

    // (a+w)-b

    let mut v = 0;

    if a+w < b {
        v = (a+w)-b;
    } else if b+w < a{
        v = a-(b+w);
    } else {
        v = 0;
    }

    println!("{}",v.abs());
    
}