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'.

Ex Input:
A gas-operated firearm operates on a similar principle of a car engine. When a round is fired, expanding gases propel the bullet out of the barrel, along with most of the gas. But a small portion of the gas is siphoned off into a seperate gas tube either above or below the barrel and forces a piston backwards, which in turn pushes back the bolt carrier, ejects the spent brass, and is pushed forward again by a recoil spring, stripping a fresh round out of the magazine and pushes it into the chamber to be fired. A blowback- operated firearm is comparatively simple. When a round is fired in a blowback-operated firearm, the bolt is forced back by the recoil energy of the spent brass itself, eliminating the need for a piston. The downiside to the simpler design is increased recoil, since not all of the expanding gases in a gas-operated firearm actually exit the barrel, there is less gas pushing the muzzle up and back. the blowback system is often found on smaller weapons, such as pistols and sub-machine guns, because it is simpler and requires fewer parts, which allows a weapon to be small and lightweight.

Ex Output:
6


Ex Input:
Donate canned food and your time and services to those in need.

Ex Output:
9


Ex Input:
GameFly.com rents both PSP movies and games.  (They're in seperate categories if you don't see them right away.)\n\nI've been a customer for about a year, and I think their selection and customer service are both stellar.  Ship times seem a little longer than Netflix, and pricing is higher (for good reason).\n\nI love the packaging (in addition to the Netflix style paper envelopes there's a hard cardboard shield) and I've never received a defective game.  The pre-owned purchase program is also a nice touch.

Ex Output:

7


