DYI Construction Co. is considering a new inventory system that will cost​ $750,000. The system is expected to generate positive cash flows over the next four years in the amounts of​ $350,000 in year​ one, $325,000 in year​ two, $150,000 in year​ three, and​ $180,000 in year four.​ DYI's required rate of return is​ 8%. What is the payback period of this​ project?