let () =
    let n, k = Scanf.scanf "%d %d\n" @@ fun a b -> a, b in
    let arr = Array.init n @@ fun _ -> Scanf.scanf "%d " @@ fun d -> d in
    let () = Array.fast_sort (fun x y -> y-x) arr in
    let (ans, _) = Array.fold_left
        (fun (ans, i) b -> if i < k && b > 0 then (ans+b, i+1) else (ans, i+1))
        (0,0) arr in
    print_int ans