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

Input:
Product title: Tanglewood Cedar/Mahogany Guitar, Natural Satin (TW28-CLN)
Product description: From our Evolution Series, the TW28-CLN is a Dreadnought acoustic guitar with Cedar top and Mahogany back & sides. Natural Satin finish.
Product feature: Cedar Top, Mahogany back and side, Dreadnought
Product brand: Tanglewood
Target attributes: Number of Strings
Answer: attribute: number of strings
value: None
source: None