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: Time Limit Exceeded)

import Control.Monad
import qualified Data.Sequence as S

check [] _ = []
check (x:xs) seq
    | S.elemIndexL x seq == Nothing = x : check xs (x S.<| seq) 
    | otherwise                     = check xs seq

toInt x = read x :: Int

main = do
    n <- readLn
    s <- replicateM n getLine
    print $ length $ check s S.empty