Problem:
Score : 200 points

Problem Statement

An X-layered kagami mochi (X ≥ 1) is a pile of X round mochi (rice cake) stacked vertically where each mochi (except the bottom one) has a smaller diameter than that of the mochi directly below it. For example, if you stack three mochi with diameters of 10, 8 and 6 centimeters from bottom to top in this order, you have a 3-layered kagami mochi; if you put just one mochi, you have a 1-layered kagami mochi.

Lunlun the dachshund has N round mochi, and the diameter of the i-th mochi is d_i centimeters. When we make a kagami mochi using some or all of them, at most how many layers can our kagami mochi have?

Constraints

1 ≤ N ≤ 100

1 ≤ d_i ≤ 100

All input values are integers.

Input

Input is given from Standard Input in the following format:

N
d_1
:
d_N

Output

Print the maximum number of layers in a kagami mochi that can be made.

Sample Input 1

4
10
8
8
6

Sample Output 1

3

If we stack the mochi with diameters of 10, 8 and 6 centimeters from bottom to top in this order, we have a 3-layered kagami mochi, which is the maximum number of layers.

Sample Input 2

3
15
15
15

Sample Output 2

1

When all the mochi have the same diameter, we can only have a 1-layered kagami mochi.

Sample Input 3

7
50
30
50
100
50
80
30

Sample Output 3

4

Solution in Haskell (GHC 7.10.3) (judge verdict: Accepted)

{-# LANGUAGE OverloadedLists     #-}
{-# LANGUAGE OverloadedStrings   #-}
{-# LANGUAGE ScopedTypeVariables #-}

import           Control.Monad
--import           Control.Monad.Loops
import           Data.IORef
import           Data.Maybe
import qualified Data.Text     as T
import qualified Data.Text.IO  as T
import           GHC.Base
import           System.IO

import qualified Data.Array    as A
import qualified Data.IntMap   as I
import           Data.List
import qualified Data.Map      as M
import qualified Data.Set      as S
import qualified Data.Vector   as V

-- for Text
(+.+) = T.append
(!.!) = T.index

-- for Vector
count :: (a -> Bool) -> V.Vector a -> Int
count p = V.length . V.filter p

-- for IO
readT :: Read a => T.Text -> a
readT = read . T.unpack

getLineSpc :: Read a => IO [a]
getLineSpc = do
  t <- T.getLine
  let xs = map readT $ T.split (== ' ') t
  return xs

getLineSpcVec :: Read a => IO (V.Vector a)
getLineSpcVec = do
  t <- T.getLine
  let xs = V.fromList $ map readT $ T.split (== ' ') t
  return xs

----------
-- main --
----------
main :: IO ()
main = kagamiMochi

kagamiMochi :: IO ()
kagamiMochi = do
  n  :: Int   <- readLn
  ds :: [Int] <- replicateM n readLn
  print $ length $ nub ds