Consider the following threeminusyear project. The initial afterminustax outlay or afterminustax cost is​ $1,500,000. The future afterminustax cash inflows for years​ 1, 2, 3 and 4​ are: $800,000,​ $800,000, $300,000 and​ $100,000, respectively. What is the payback period without discounting cash​ flows?