In March of the current year, Star Corporation, a calendar year corporation, purchased and placed into service a building costing $$400,000$ and land costing $$150,000.$ Later that year, on November $15,$ the corporation purchased and placed into service office equipment costing $$80,000.$ No other equipment or real estate was placed into service during the year. Under the MACRS depreciation system, what convention must Star Corporation use?