let modulo = 2019
let ( *% ) a b = (a * b) mod modulo
               
let () =
  let (l, r) = Scanf.sscanf (input_line stdin) "%d %d" (fun a b -> (a, b)) in
  let rec loop_l : int -> int = fun i ->
    if i > r then 2019 else
      let rec loop_r : int -> int = fun j ->
        if j > r then 2019
        else min (i *% j) (loop_r (j + 1)) in
      min (loop_r (i + 1)) (loop_l (i + 1))
  in
  let ans = if l - r > 2019 then 0
            else loop_l l in
  print_int ans;
  print_newline ()