The statement will help the manager keep track of the gift items to give away:
The manager in charge of a department store, he or she decided to give the gift for certain product purchased by customer, He or she has to create a product code which is called buy and get as a one category and attach the list the product.
Once customer has purchased item, software should able to deduct the stock properly.
So programming statement should have list of product as singe product to do the necessary sales.
Software also keep track on stock deduction and keep sales of gift item as free of cost product.