A retailer using the periodic review order-up-to model with review period 1 week and lead time 6 weeks saw a demands of 88 units nine weeks ago, 68 eight weeks ago, 49 seven weeks ago, 81 six weeks ago, 44 five weeks ago, 21 four weeks ago, 21 three weeks ago, 42 two weeks ago and 35 units last week. How many units will be in the shipment the retailer will receive at the start of this week?