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.sum() |> loli
    end
  end

  def loli(n) do
    case n do
      0 ->
        0

      _ ->
        case n |> rem(9) do
          0 -> 9
          _ -> n |> rem(9)
        end
    end
  end
end