A building is expected to require R1 million in capital improvement expenditures in five years. The building's net operating cash flow prior to that time is expected to be at least R20 000 at the end of every month. How much of that monthly cash flow must the owners set aside each month in order to have the money available for the capital improvements, assuming the equal monthly contributions placed in this "sinking fund" will earn interest at a nominal annual rate of 6%, compounded monthly