"Food Service Industries is considering replacing an old food dispenser which was purchased 10 years ago at a cost of $25,000. It has a current market value of $5000. If the firm spends $3000 to recalibrate the dispenser, it would extend the life of the dispenser for another three years with the following estimated market values and operating costs: Year 0: Market value $5000; Overhaul $3000 Year 1: Market value $3900; O&M cost $3800 Year 2: Market value $2300; O&M cost $4600 Year 3: Market value $1000; O&M cost $6400 The firm`s MARR is 14%. Ignore any income tax effects for this problem. What is the remaining economic service life of the machine with the overhaul? Hint: consider the overhaul as one-time O&M cost in year 0. Enter your answer as an integer between 1 and 3."