Exercise 3: Give an ERD for the following system. Consider a retail company composed of 4 stores in Vietnam. These stores sell 2500 different products in 50 categories from 50 different providers. Note that each product is provided by a single provider. One product could belong to many categories (food, rice, ...). Information about the products contains name, description, selling price, provider (given name, last name, address, phone number), product categories. The information about the shops is address, district, city, telephone. Each shop could have several employees (name, phone number, email, date of birth, start date). Note that every shop has only one current manager (who is also an employee) and we keep track only the current manager of each shop in the database. The sales of products are grouped into invoices including: the date of the sale, the shop where the invoice is emitted, the employee who emitted the invoice, the list of products sold and for each product, the quantity sold. The invoice also mentions the information of the customer including the name, the phone number, the date of birth, the address, the district, and the city. The information about the stocks of each product in each store include the remaining quantity of each product in each store