A takes a loan for 7 years with principle amount $5,000mn.He proposes to repay $ 250 mn at the end of Year 1, $750 mn at the end of Year 2, and $ 1,500 mn at the end of Year 3, plus a fixed but currently unspecified cash flow at the end of Years 4 through 7. If rate of interest is at 8%. What annual cash flow must be paid by A at the end of each of the final 4 years, to clear the loan obligations.