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

  def solve([a, b]) do
    cond do
      a == b || 2 * a == b -> 4
      a < b && b < 2 * a -> 8
      true -> 0
    end
  end
end