let z = 12345

let p s =
  let rec doit i =
    if i > z then false
    else s = string_of_int i || doit (i + 1) in
  doit 0

let () =
  let a = read_line () in
  let b = read_line () in
  print_endline (if p a && p b then "OK" else "NG")