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

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

  defp solve(list) do
    list
    |> Enum.count(&(&1 <= Enum.sum(list) |> div(10)))
    |> (&(&1 * 30)).()
  end
end