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: MSI C Series CX61 0NF-257US 15.6-Inch Laptop (Brown)
Product description: MSI CX61 0NF-257US: 15.6-inch HD Laptop with Core i5-3210M, GT645M/2GB DDR3, DVD SuperMulti drive and Windows 8
Product feature: Intel Core i5 3210M 2.5 GHz (3 MB Cache), 6 GB SO-DIMM, 750 GB 5400 rpm Hard Drive, 15.6-Inch Screen, NVIDIA GeForce GT 645M, Windows 8
Product brand: MSI
Target attributes: Screen Size
Answer: attribute: screen size
value: 15.6-inch
source: product description
attribute: screen size
value: 15.6-inch
source: product title
attribute: screen size
value: 15.6-inch
source: product feature