Instruction: Parse the product information to locate the target attribute, and then provide the extracted value of the target attribute and its source in the output, specifying None if the attribute is not present.

Input:
Product title: Dell Inspiron 17 5000 Series FHD 17.3-Inch Touchscreen Laptop (Intel Core i7 5500U, 16 GB RAM, 1 TB HDD, Silver) with MaxxAudio
Product description: Do every task better on a spacious 17" laptop that's full of style. It's packed with potential. Just like you.
Product feature: Intel Core i7 5500U 2.4 GHz Processor, 16 GB DDR3L SDRAM, 1 TB HDD Storage; Tray load DVD Drive (Reads and Writes to DVD/CD), 17.3 Inch FHD (1920x1080) LED-lit Truelife Touchscreen, Windows 8.1 Operating System; Silver Chassis, Cortana: Your own personal, digital secretary., Start Menu: Your expanded Windows 7 Start menu is here., Continuum: Switching between 2-in-1 devices has never been easier., Microsoft Edge: A new web browser loaded with cool features like writing or typing directly on a webpage., Speed: Windows 10 starts up and resumes fast for your busy lifestyle.
Product brand: Dell
Target attributes: Screen Size
Answer: attribute: screen size
value: 17.3 inch
source: product feature
attribute: screen size
value: 17.3-inch
source: product title