Sapphire sells two products: ordinary laptops and premium laptops. Ordinary laptops are priced at $$655$ each and premium laptops are priced at $$1,150$ each. The variable cost per unit is $$605$ per ordinary laptop and $$1,090$ per premium laptop. Total fixed cost is $$143,000.$ Sapphire's expected sales mix is four ordinary laptops to one premium laptop. Calculate the break$-$even point in units for ordinary laptops.