Dave is considering investing in a new app for his mobile website. The initial cost is $100,000. However, Dave believes that the new app will generate more page views and thus more advertising revenue. He predicts that the new app will generate incremental cash flows of 20,000 per year for the next four years. Assume that the cash flows are realized at the end of the year and that Dave's discount rate is 7 percent. What is the NPV of the new app? (Do not include dollar signs or commas in your answers)