After you graduate, you plan to work for another twenty years and then retire and move to a low-cost area. You think you can save $2500 a year for the first 5 years, and $3500 a year for the next 10 years, and $6000 a year for the last 5 years. If you can earn 3.5% a year on your savings in a reasonably safe investment, how much will you have from these savings when you retire?