The MRP gross requirements for item A are shown here for the next $10$ weeks. Lead time for A is three weeks and setup cost is $$10.$ There is a carrying cost of $$0\mathrm{.}010$ per unit per week. Beginning inventory is $100$ units.

WEEK

$12345678910$

Gross requirements $4040203060802060205100$

Use the least total cost or the least unit cost lot$-$sizing method to determine when and for what quantity the first order should be released.