Problem:
Score : 300 points

Problem Statement

You drew lottery N times. In the i-th draw, you got an item of the kind represented by a string S_i.

How many kinds of items did you get?

Constraints

1 \leq N \leq 2\times 10^5

S_i consists of lowercase English letters and has a length between 1 and 10 (inclusive).

Input

Input is given from Standard Input in the following format:

N
S_1
:
S_N

Output

Print the number of kinds of items you got.

Sample Input 1

3
apple
orange
apple

Sample Output 1

2

You got two kinds of items: apple and orange.

Sample Input 2

5
grape
grape
grape
grape
grape

Sample Output 2

1

Sample Input 3

4
aaaa
a
aaa
aa

Sample Output 3

4

Solution in Haskell (GHC 8.8.3) (judge verdict: Accepted)

import Control.Monad
import Data.List
import qualified Data.ByteString.Char8 as BS
import qualified Data.Set as Set

main :: IO ()
main = do
  n <- readLn
  s <- replicateM n BS.getLine
  print $ length $ ordNub s
  
ordNub :: Ord a => [a] -> [a]
ordNub xs = foldr (\x k s -> if Set.member x s then k s else x:k(Set.insert x s)) (const[]) xs Set.empty