defmodule Main do
  def main do
    IO.read(:line)

    IO.read(:line)
    |> String.trim()
    |> String.split()
    |> Enum.map(&String.to_integer/1)
    |> solve()
    |> IO.puts()
  end

  def solve(p) do
    q =
      p
      |> Enum.map(&loli/1)

    cond do
      0 in q ->
        0

      true ->
        q
        |> Enum.reduce(fn x, acc -> (x * acc) |> loli end)
        |> loli
    end
  end

  def loli(n) do
    cond do
      n == 0 -> 0
      n |> rem(9) == 0 -> 9
      true -> n |> rem(9)
    end
  end
end