let chr_to_num c = Char.code c - Char.code '0'

let p s =
  let n = String.length s in
  let x = chr_to_num s.[0] in
  if x < 1 || x > 9 then n = 1 && x = 0
  else
    let rec doit i =
      if i = n then true
      else
        let x = chr_to_num s.[i] in
        x >= 0 && x <= 9 && doit (i + 1) in
    doit 1

let z = 12345

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