How do i get the book value of a note payable?

Part 2. Wolfer Corp. issued a Note Payable (i.e., borrowed) sometime ago when the interest rate was 5% compounded annually. The note is tradable. Payments are made annually on Dec 31st.

It is now 1/1/19. The only remaining payment on the note, as sketched below, is an amount $Z at maturity (12/31/22).

Payments$ Z

01234

(1/1/19)(12/31/19)(12/31/20)(12/31/21)(12/31/22)

A. What is the book value of the Note on Wolfer's books on 1/1/19 (as an expression in terms of Z)?