Instruction: Given the title, description, feature, price, and brand of a product and a set of target attributes, extract the value of each target attribute from the product information. Output the extracted value and the corresponding source (e.g., title or feature) denoting where the value is extracted.

Input:
Product title: Alienware 17R3 Intel Core i7-6700HQ X4 2.6GHz 16GB 1TB HDD + 256GB SSD 17.3" Win10,Silver
Product description: Introducing the new Alienware 17, the gamers choice for power and performance. A 17-inch laptop, featuring Intel Core i7 processor with dynamic overclocking, an FHD screen. Windows 10, a solid state primary drive plus storage drive and an NVIDIA GTX series card for the gaming performance you have been asking for.
Product feature: Intel Core i7-6700HQ 2.6GHz; 1000GB SATA; 16GB DDR4, 17.3" IPS display; 1920 x 1080; NVIDIA GeForce GTX 980M, 802.11A,802.11AC,802.11B,802.11G,802.11N; Bluetooth 4.0 + HS; Microsoft Windows 10 Home, Backlit Keyboard; No Optical Drive; 6 Hours Battery Life, Dedicated NVIDIA GeForce GTX 980M (4.0GB Dedicated Video Memory)
Product brand: Alienware
Target attributes: Number of Cores
Answer: attribute: number of cores
value: None
source: None