fun member x nil = false
  | member x (h::tl) =
    if x = h
    then true
    else member x tl


fun readInt () =
    valOf (TextIO.scanStream (Int.scan StringCvt.DEC) TextIO.stdIn)


fun readStr () =
    let
        fun scan reader stream = SOME (StringCvt.splitl (not o Char.isSpace) reader (StringCvt.skipWS reader stream))
    in
        valOf (TextIO.scanStream scan TextIO.stdIn)
    end


val () =
    let
        val n = readInt ()
        val s_s = List.tabulate (n, fn _ => readStr ())
                                    
        val ans = List.length
                      (List.foldl
                           (fn (s, acc) =>
                               List.foldl
                                   (fn (s1s2, innerAcc) =>
                                       if s1s2 = "" orelse member s1s2 innerAcc
                                       then innerAcc
                                       else s1s2 :: innerAcc)
                                   acc
                                   (List.map
                                        (fn ss =>
                                            if s = ss then ""
                                            else s ^ ss)
                                        s_s))
                           []
                           s_s)
    in
        print (Int.toString ans ^ "\n")
    end