fn read_i32() -> i32 {
    let mut line = String::new();
    std::io::stdin().read_line(&mut line).unwrap();
    line.trim().parse().unwrap()
}

fn main() {
    let N = read_i32();
    let K = read_i32();
    let mut n = vec![0; N as usize];
    for i in 0..N {
        n[i as usize] = read_i32();
    }
    n.sort();
    println!("{}", n[n.len() - 1] - n[0]);
}