A bin activator has an initial cost of $34,000 and a salvage value described by S = 34,000 - 3300k, where k is the number of years since the bin activator was purchased. The net annual revenue is estimated by R = 5000 + 600k. The equipment will have a maximum useful life of 5 years. If the company's MARR is 4% per year, when is the best time to abandon the equipment?