Two payments of $$2000$ each are scheduled for six months from now and two years from now. They are to be rescheduled as follows: a payment one year from now and a second payment, half the size of the first payment, three years from now. What must the amount of each payment be for the replacement stream to be equivalent to the originally scheduled stream? Assuming that money can earn $3\mathrm{.}8\%$ compounded semiannually.