import qualified Data.ByteString.Char8 as C
import qualified Data.IntMap.Strict as M
import Data.Maybe (fromJust)

appendNumber :: Int -> M.IntMap Int -> M.IntMap Int
appendNumber x = M.insertWith (+) x 1

countNovelNumbers :: [Int] -> Int
countNovelNumbers = M.size .
    M.filter (== 1) . foldr appendNumber M.empty

unsafeReadInt :: C.ByteString -> Int
unsafeReadInt = fst . fromJust . C.readInt

main :: IO ()
main = do
    _ <- C.getLine
    print . countNovelNumbers .
        map unsafeReadInt . C.words =<< C.getLine