I don't understand which formula to use for it Marco Chip, Inc. just issued zero-coupon bonds with a par value of $1,000.

 I need help answering this question. I don't understand which formula to use for it

Marco Chip, Inc. just issued zero-coupon bonds with a par value of $1,000. The bond has a maturity of 28 years and a yield to maturity of 14.71 percent, compounded semi-annually. Please assist.