import Control.Applicative ((<$>))
import Control.Monad (replicateM)
import Data.List

main :: IO ()
main = do
  n <- getl read
  solve <$> replicateM n (getl read) >>= print

solve :: [Int] -> Int
solve = length . nub . sort

getl :: (String -> a) -> IO a
getl f = f <$> getLine
