import Control.Monad

delDupe :: [String] -> [String] -> [String]
delDupe [] _ = []
delDupe (x:xs) lst
    | x `notElem` lst = x : delDupe xs (x : lst)
    | otherwise        = delDupe xs lst

main = do
    n <- readLn
    s <- replicateM n getLine
    print $ length $ delDupe s []