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

    ans =
      (for a <- 0..25, b <- 0..25, c <- 0..25, d<- 0..25,
        do: "a#{List.to_string([a + 97, b + 97, c + 97, d + 97])}a")
      |> Enum.take(n - 1)
      |> Enum.concat(["an"])

    IO.puts Enum.join(ans, "\n")
  end
end