let in_pat = Str.regexp "^[1-9][0-9]*$"

let check_input str =
  str = "0" ||
  (String.length str <= 5 &&
   Str.string_match in_pat str 0 &&
   int_of_string str <= 12345)

let () =
  let a = read_line ()
  and b = read_line ()
  in
  ((check_input a) && (check_input b)) |>
  (function | true -> "OK" | false -> "NG") |>
  print_endline