Mathematical work please, not interested in excel work.

Consider a $1000 par value 10-year 4% bond with semiannual coupons. The bond is callable at $1100 on any coupon date starting 5 years after issue for the 5 years that follow, except for the maturity date when the bond matures at $1000. What is the highest price an investor can pay for this bond to be assured of a yield of 5% convertible semiannually, no matter whether the bond is called or not?