let n = read_int()

module SS = Set.Make(String)

let rec f i ans set =
  if i = n then ans
  else
    let s = read_line () in
    if SS.mem s set then f (i + 1) ans set
    else f (i + 1) (ans + 1) (SS.add s set)

let () = print_int (f 0 0 SS.empty)
