A firm has established a distribution network for the supply of a raw material critical to its manufacturing. Currently there are two origins (warehouses) for this raw material, which must be shipped to three manufacturing facilities (factories). The current network has the following characteristics:

Costs	Factory1	Factory2	Factory3	Capacity
Warehouse1	$19	$15	$14	660
Warehouse2	$14	$17	$13	640
Demand	660	320	180	1160\1300

What is the constraint for Factory 2? Use whole numbers.