instruction:
You are given a passage. Using the information present in the passage, you need to classify it into one of the 10 topics: 0 - 'Society & Culture', 1 - 'Science & Mathematics', 2 - 'Health', 3 - 'Education & Reference', 4 - 'Computers & Internet', 5 - 'Sports', 6 - 'Business & Finance', 7 - 'Entertainment & Music', 8 - 'Family & Relationships', 9 - 'Politics & Government'.
question:
The best article I've read on the subject is in the link below.  In summary, the article cites the following 7 factors common to Web 2.0:\n\n* Services, not packaged software, with cost-effective scalability\n* Control over unique, hard-to-recreate data sources that get richer as more people use them\n* Trusting users as co-developers\n* Harnessing collective intelligence\n* Leveraging the long tail through customer self-service\n* Software above the level of a single device\n* Lightweight user interfaces, development models, AND business models
answer:
4


question:
The Wall stretches over a formidable 6,350 km (3,946 miles), from Shanhai Pass on the Bohai Gulf in the east, at the limit between China proper and Manchuria, to Lop Nur in the southeastern portion of Xinjiang Uygur Autonomous Region.
answer:
3


question:
Tinkerbell is the name of her chihuahua, who famously went missing last year but was soon after found hiding in Paris's closet!
answer:

7


