let modulo = 2019
let ( *% ) a b = (a * b) mod modulo

exception Zero
        
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 min_i = 0 then raise Zero
    else if i >= r then min_i else
      let rec loop_r j min_j =
        if min_j = 0 then raise Zero 
        else 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 = try (if l - r > 2019 then 0
                 else loop_l l 2019)
            with Zero -> 0 
  in
  print_int ans;
  print_newline ()
