defmodule Main do
  def input, do: IO.read(:line) |> String.trim
  def ii, do: input() |> String.to_integer
  def li, do: input() |> String.split |> Enum.map(&String.to_integer/1)
  def yn(b), do: (if b, do: "Yes", else: "No")

  @mod 10 ** 12
  def main do
    n = ii()
    ans = f(1, n, 1)
    IO.puts ans
  end

  def f(_, _, 0), do: 0
  def f(x, n, t) do
    cond do
      x > n -> t
      true -> f(x+1, n, rem(x*t, @mod))
    end
  end
end