fn main() {
    let mut nk = String::new();
    std::io::stdin().read_line(&mut nk).ok();
    let nk: Vec<usize> = nk.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let n = nk[0];
    let k = nk[1];
    let mut a = String::new();
    std::io::stdin().read_line(&mut a).ok();
    let mut a: Vec<isize> = a.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    a.sort();
    let result: isize = a.iter().rev().take(k).filter(|i| **i > 0).sum();
    println!("{}", if result == 0 { a[n-1] } else { result });
}