import Control.Monad

nonDupe ([], lst) = snd ([], lst)
nonDupe ((x:xs), lst)
    | x `notElem` lst  = nonDupe (xs, (x:lst)) 
    | otherwise      = nonDupe (xs, lst)

main = do
    n <- readLn
    s <- replicateM n getLine
    print $ length $ nonDupe (s, [])