Given the task definition, example input & output, solve the new input case.
In this task, you're given an article and an answer. Your task is to generate the question for the answer based on the given article.
Example: Article: There are a lot of public libraries in Britain. These libraries have more than one hundred and fifteen million books, not including those libraries of public schools. Public libraries not only lend books, music records but also help children, patients in hospitals and others to get special play readings, film shows and so on. The first public libraries were founded in about the year 1850. Today's public libraries usually have a reading-room, a lending room and a reference room. The greatest and most famous library in Britain is that of the British Library in London. It was founded in 1973 and has over 10, 000, 000 books. It has nearly every magazine, newspaper and book published in Britain and other parts across the world.
Answer: 10,000,000 or less.
Output: How many books are there in the British Library?
In the Article, 10,000,000 is mentioned for the number of books available in the British Library, so this is a good question.

New input case for you: Article: If you have ever experienced jet lag ,you know how much of a drag it can be. Jet lag happens as a result of air travel, when traveling between two or more time zones. Your body is used to operating in a certain time zone, and when its timing is affected, you're likely to have problems. Edward Norton's character in the movies Fight Club faces the struggle of jet-lag-induced sleeplessness due to his constant traveling. Sleeplessness is just one of the effects of jet lag, and it can lead to other problems, such as tiredness, memory loss and confusion. That's not something you should have to fight on a business trip and it certainly won't make your vacation very enjoyable, either. Sleeplessness is the biggest problem for travelers that suffer from jet lag. Don't worry. You can do something to prevent it. Modify Your Body Clock To prevent the effects on your body's timing that come with crossing time zones, you need to change your body clock sooner, rather than later. You can do this by putting yourself on the same time as your destination time zone before you fly. If you know that you will be traveling to London from the eastern United States, you'll have a five-hour time difference to deal with. Plan for it. Avoid Heavy Food and Alcohol Part of the pleasure of flying commercially, especially if you fly business or first class, is taking advantages of the food and drinks. If you want to avoid jet lag, though, you should think twice. Eating heavy food will only make the jet lag worse. It isn't good to drink alcohol during a flight, either, because it may make you drowsy. Wait until your body adjusts before you decide to have heavy food or drink alcohol.
Answer: How jet lag happens and tips on traveling safely.
Output:
What is the main idea of the passage?