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)

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