-- yukicoder My Practice
-- author: Leonardone @ NEETSDKASU

main = getContents >>= putStrLn . solve . words

solve [a,b] = if check a && check b then "OK" else "NG"

check xs@(x:_)
    | checkAllNum xs = let v = read xs
                       in if x == '0' then v == 0 else v <= 12345
    | otherwise = False

checkAllNum [] = True
checkAllNum (x:xs)
    | '0' <= x && x <= '9' = checkAllNum xs
    | otherwise = False