let n = Scanf.sscanf (read_line ()) "%d" @@ fun n -> n
let s = Array.init n @@ fun _ -> read_line ()

module SSet = Set.Make(struct type t = string let compare = compare end)

let () = Printf.printf "%d\n"
  @@ SSet.cardinal
  @@ Array.fold_left (fun set s -> SSet.add s set ) SSet.empty s