Huai takes out a $3500 student loan at 6.5% to help him with 2 years of community college. After finishing the 2 years, he transfers to a state university and borrows another $12,900 to defray expenses for the 5 semesters he needs to graduate. He graduates 4 years and 4 months after acquiring the first loan and payments are deferred for 3 months after graduation. The second loan was acquired 2 years after the first and had an interest rate of 7.8%. Find the total amount of interest that will accrue until payments begin.