John Company expects to sell 50,510 units of finished goods over the next three-month period. The company has 21,480 units on hand and its managers want to have 29,390 units on hand at the end of the period. To produce one unit of finished product, 3 units of direct materials are needed. John has 117,910 units of direct material on hand and has budgeted for an ending inventory of 160,270 units. What is the amount of direct material to be purchased (in units)?