There is a project that we have been hired to inform the decision maker whether to undertake or not. The project cost c today and does not yield any cash flow today. At t=1 it will yield x1; at t=2 x2; at t=3 x3; at t=4 x4; at t=5 x5. What is the NPV? Should we invest on the project or not? Assume that the interest rate is y%.