use std::io;
use std::io::prelude::*;
use std::io::BufReader;

fn run(args: &Vec<String>) -> Vec<String> {
    //let n: u32 = args[0].parse().unwrap();
    //let k: u32 = args[1].parse().unwrap();
    let mut ns: Vec<u32> = args[2..].iter().map(|s| s.parse::<u32>().unwrap()).collect();

    ns.sort();
    let r = ns.last().unwrap() - ns.first().unwrap();
    vec!(r.to_string())
}

fn main() {
    let args = lines(BufReader::new(io::stdin()));
    for line in run(&args) {
        println!("{}", line);
    }
}

fn lines<R: Read>(reader: BufReader<R>) -> Vec<String> {
    reader.lines().map(|l| l.unwrap()).collect()
}