import Control.Monad.ST
import Data.Foldable (foldrM)
import Data.HashTable.ST.Basic as H
import Data.List (nub)
import Data.Maybe (mapMaybe)

import Debug.Trace

type S s = H.HashTable s String [String]

-- Return Nothing if no match; unmatched remainder (can be []) if
-- match.
match :: String -> String -> Maybe String
match xs [] = Just xs
match (x:xs) (y:ys) | x == y    = match xs ys
                    | otherwise = Nothing
match [] _ = Nothing

matchAny :: S s -> [String] -> String -> ST s [String]
matchAny s yss xs = do
  t <- H.lookup s xs
  case t of
    Nothing -> let r = mapMaybe (match xs) yss
               in H.insert s xs r >> return r
    Just x -> return x

check :: S s -> [String] -> String -> ST s Bool
check s yss xs = do
  zss <- nub <$> matchAny s yss xs
  if [] `elem` zss
    then return True
    else anyM (check s yss) zss

anyM :: Monad m => (a -> m Bool) -> [a] -> m Bool
anyM p = foldrM f False
  where
    f a b = (b ||) <$> p a

parseTowels :: String -> [String]
parseTowels = map init . words

parse :: String -> ([String],[String])
parse s = let yss = filter (not . null) . drop 2 $ lines s
              xss = parseTowels . head $ lines s
          in (xss, yss)

run :: [String] -> [String] -> ST s Int
run xss yss = do
  ht <- H.new :: ST s (S s)
  length . filter id <$> traverse (check ht yss) xss

main :: IO ()
main = do
  input <- getContents
  let (xss, yss) = parse input
  print $ runST $ run yss xss