open Array
let () =
    let n, k = Scanf.scanf "%d %d\n" @@ fun a b -> a, b in
    let lst = to_list (init n @@ fun _ -> Scanf.scanf "%d " @@ fun d -> d) in
    let rec f lst k = if k = 0 then 0 else match lst with
        | [] -> 0
        | h :: t -> if h > 0 then h + f t (k-1) else 0 in
    List.fast_sort compare lst;
    print_int (f lst k)