Bell Computers purchases integrated chips. The ordering cost is $120 per order, and sales are steady, at 400 per month. The companys supplier, Rich Blue Chip Manufacturing, Inc., offers price concessions in order to attract larger orders. The price structure is shown below.

Quantity Purchased	Price/Unit
[1,49)	390
[50-99)	350
[100-600)	325
600 or more	270

The holding cost per chip per year is 10% of the chip price.

What is the optimal order quantity? (Round to the nearest integer, if necessary).