Jerusalem Medical Ltd., an Israeli producer of portable kidney dialysis units and other medical products, develops a 4-month aggregate plan. Demand and capacity (in units) are forecast as follows: Capacity Source Labor Month 1 Month 2 Month 3 Month 4 Regular time Overtime Subcontract Demand 245 265 15 28 12 260 17 310 280 300 28 13 15 305 311 The cost of producing each dialysis unit is $875 on regular time, $1,310 on overtime, and $1,600 on a subcontract. Inventory carrying cost is $100 per unit per month. There is to be no beginning or ending inventory in stock and backorders are not permitted. Minimizing cost using the transportation method, the optimal cost is $(enter your response as a whole number).