module Main where
import qualified Control.Monad as C
import qualified Data.Char as C
import qualified Data.List as L
import qualified Data.Map as M
import qualified Data.Array as A

int = read :: String -> Int
getWord :: IO String
getWord = do
  c <- getChar
  if C.isSpace c
  then
    return []
  else do
    ws <- getWord
    return (c:ws)
getInt = fmap int getWord
replace pred a = map (\x -> if pred x then a else x)

main = interact $ printer . solver . parser
parser = id
printer = unlines . (:[])

solver ss 
  | isMonth ai && isMonth bi = "AMBIGUOUS"
  | isMonth ai = "MMYY"
  | isMonth bi = "YYMM"
  | otherwise = "NA"
  where
    (a,b) = splitAt 2 ss
    ai = int a
    bi = int b

isMonth a = 1 <= a && a <= 12
