A perpetuity costs $ 80 (price of perpetuity at = 0) and makes annual payments at the end of the year. The perpetuity pays $1 at the end of year 2, $2 at the end of year 3, , and $ at the end of year ( + 1). After year ( + 1), the payments remain constant at $ . The nominal interest rate is 10% convertible semiannually. Calculate $ n