fn main() {
    let v = read_vec::<usize>();
    let (n, k) = (v[0], v[1]);
    assert!(1 <= n);
    assert!(n <= 100);
    assert!(1 <= k);
    assert!(k <= 100);
    let mut a = read_vec::<i64>();
    assert!(a.iter().all(|a| a.abs() <= 100));
    assert!(a.len() == n);

    a.sort();
    a.reverse();
    let mut ans = a[0];
    ans += a.iter()
        .skip(1)
        .take(k - 1)
        .take_while(|&&x| x >= 0)
        .sum::<i64>();
    println!("{}", ans);
}

fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}

fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>()
        .split_whitespace()
        .map(|e| e.parse().ok().unwrap())
        .collect()
}