An annuity with 36 monthly payments has a first payment of $600 one month from today. Starting with the second payment, the next 15 monthly payments increase so that each payment is 4% larger than the previous payment. Furthermore, starting with the 17th payment, the next 20 monthly payments decrease so that each payment is 5% smaller than the previous payment. What would be the accumulated value of this annuity immediately after the last payment, if the annual effective interest rate is 6%?