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 i min_i =
    if i >= r then min_i else
      let rec loop_r j min_j =
        if j > r then min_j
        else loop_r (j + 1) (min (i *% j) min_j) in
      loop_l (i + 1) (min (loop_r (i + 1) 2019) min_i) 
  in
  let ans = if l - r > 2019 then 0
            else loop_l l 2019 in
  print_int ans;
  print_newline ()
