Cocos

cocos.ex

defmodule Cocos do
  def test_amount x do
    if check_division x, 7 do
      x
    else
      test_amount x + 1
    end
  end

  defp check_division _, 0 do
    true
  end

  defp check_division n, m do
    if rem(n, 7) == 1 do
      check_division div(n, 7), m - 1
    end
  end
end

IO.puts Cocos.test_amount(1)