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

Input:
Product title: AMD Athlon II X4 651K AD651KWNZ43GX 3.0GHz 4MB Quad-Core CPU Processor Socket FM1 905-pin 100W
Product description: Content: 1x CPU 1x Thermal Compound(free gift). CPU only (you need to heat grease and heatsink/fan to install). Fully tested in perfect working condition.
Product feature: Frequency: 3000 MHz, Socket FM1, 4 cores, 4 threads, Level 2 cache:4 MB, Thermal Design Power: 100 Watt, Warranty:3 month
Product brand: AMD
Target attributes: Number of Cores
Answer: attribute: number of cores
value: athlon ii x4
source: product title
attribute: number of cores
value: quad-core
source: product title
attribute: number of cores
value: 4 cores
source: product feature