import Control.Monad
import qualified Data.Sequence as S

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

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