Instruction: Using the product's title, description, features, price, and brand, identify and retrieve the values associated with a specified set of target attributes. Output the extracted values along with their respective sources (e.g., title or feature) indicating where each value was found.

Input:
Product title: Targus Fully Cord-Storing Optical Mouse with 2.5-Foot Adjustable USB Cord, Black (AMU76US)
Product description: The Targus Cord-Storing Optical Mouse features a patented cord storing design that retracts the 2.5 foot USB cord completely inside of the mouse for easy travel. The cord can also be adjusted to any length and the ergonomic, ambidextrous design helps prevent palm strain. Utilizing the latest 1,000 DPI optical technology for precise tracking, the Cord-Storing Optical Mouse helps keep the workspace neat without the clutter of excess cables.
Product feature: Compatible with Windows, Mac, and netbooks, Adjustable cord extends to 2.5, Ambidextrous design, 1 Year Limited Warranty, Limited warranty does not cover products purchased from 3rd party sellers
Product price: $19.30
Product brand: Targus
Target attributes: Number of Buttons
Answer: attribute: number of buttons
value: None
source: None