You are presented with an investment opportunity that will give you the following stream of cash flows: nothing for the next 3 years; starting at the following year, an amount of $4,000 per year until year 11; and after that year, then an amount of $8,000 per year until year 23. If your required rate of return (APR) is 11% compounded annually, what is the future value at end of year 23 of these cash flows?