defmodule Main do
  def main do
    k = IO.gets("") |> String.trim() |> String.to_integer()
    s = IO.gets("") |> String.trim()

    ans =
      if String.length(s) > k do
        String.slice(s, 0, k) <> "..."
      else
        s
      end

    IO.puts(ans)
  end
end