You have 600 units of a particular raw material in stock in your warehouse, of which 50 units are quarantined due to QC issues. 400 units of this stock have been reserved for already placed sales orders. Additional demand (for sales orders) for 800 units is expected during the planning period. You have active purchase orders for 200 units of this material not yet received but expected during the planning period. What is the net requirement for this material for the planning period? Show work. How will the net requirement be filled?