Instruction: Extract the value of the target attribute from the given product information and output it along with the corresponding source.

Input:
Product title: Lenovo IdeaPad Y510p 15.6-Inch Laptop (59406648) Dusk Black
Product description: A High-performance notebook with looks to match, the Idea Pad Y510p notebook looks as serious about performance as it is entertainment. The latest 4th gen Intel Core processor, high-performance, dual NVIDIA graphics and premium JBL designed audio combine to make this a true multimedia powerhouse. The Idea Pad Y510p brings video, music and games to life.
Product feature: Intel Core i7-4700MQ 2.4 GHz Processor, 16 GB DDR3 RAM, 1 TB 5400 rpm Hard Drive; 8 GB Solid-State Drive, 15.6-Inch Screen, Windows 8.1; 3-Hour Battery Life
Product brand: Lenovo
Target attributes: Number of Cores
Answer: attribute: number of cores
value: None
source: None