import Data.List
import Control.Applicative
import Control.Monad

main = do
  n <- readLn
  names <- replicateM n getLine
  let newNames = filter regal (permutations "inabameguru") \\ names
  case newNames of
    [] -> putStrLn "NO"
    _ -> putStrLn $ head newNames

regal [] = True
regal [charo] = if charo `elem` "iaeu"
                   then True
                   else False
regal (charo1 : charo2 : str) = if charo1 `elem` "iaeu"
                                   then regal (charo2 : str)
                                   else if charo2 `elem` "nbmgr"
                                           then False
                                           else regal str