A person owes $2200 at the end of 4 years and $4900 at the end of 9 years. Due to changes in their financial situation, the person was allowed to pay $1800 at the end of 2 year(s) and a final payment at the end of 12 years using 17.5% compounded annually for the settlement. Determine the amount required to settle the debt at the end of 12 years.