Cuplicious Bakery sells various bakery products. These products are grouped into several product groups. Key products for product is pro_code, and the key for product group is pro_group_code. Based on customer invoice, the additional attributes for product are pro_desc, pro_flavour and unit_price. The customer sends orders for a product. The key for order is order_code and for other attributes are order_date and quantity. The customer can place any numbers of orders or may not place any order at all. Each order is made by only one customer. The key for customer is cust_code. Other attributes are cust_name and cust_address. Each customer order consists of at least one product.

Draw an Entity Relationship Diagram for the above scenario