Southside Corporation produces and sells a single product. Expected sales for September are 13000 units, for October 14000 units, for November 9000 units, for December 10000 units and for January 15000 units. The company's desired level of ending finished goods inventory at the end of a month is 10% of the following month's expected sales in units. At the end of August, 1200 units were on hand. How many units need to be produced in the fourth quarter?