Stacey and her husband David have a joint savings account that earns 3.5% interest payable continuously and has a current balance of $56,458. Each year, David wishes to withdraw $ 4,000 payable continuously at a level rate. Stacey wishes to deposit $X at the beginning of each year so that the account will last for thirty years. What is the least X that will work? Please show by hand and not by technology.