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(h) do
    0..(length(h) - 3)
    |> Enum.map(fn i ->
      [x, y, z] = h |> Enum.slice(i, 3)

      cond do
        (x < z && z < y) ||
          (y < z && z < x) ||
          (z < x && x < y) ||
            (y < x && x < z) ->
          1

        true ->
          0
      end
    end)
    |> Enum.sum()
  end
end