Widgets R Us would like to offer a special product to its best customers. However, the firm wants to limit its maximum potential loss on this product to the firm's initial investment in the project. The fixed costs are estimated at $22,000, the depreciation expense is $13,000, and the contribution margin per unit is $13.50. What is the minimum number of units the firm should pre-sell to ensure its potential loss does not exceed the desired level? (That is the cash breakeven amount of units). Show all work