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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.

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.
Solution: How many books are there in the British Library?
Why? 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: Article: Police Officer Tidwell left the station after 8 a.m. on Sunday. He was looking forward to his day of rest. By habit he took a short cut down the path behind prefix = st1 /Digby Hall Road. Suddenly he saw a man climbing down a drain-pipe from an open bedroom window of number 29. Quietly Tidwell walked into the garden. The man had just reached the ground when he felt his arm grasped. "It seems an unlikely adventure. Would you mind explaining? " said the officer. The man was frightened, saying, "I know what's on your mind, officer, but it is a mistake. " "It's part of my job to take an interest in unusual events. I think you've just left this house in a manner other than the customary one. " Tidwell took out his notebook and a pen. "Name, address and your job and then, please, tell me your story." "Charlie Crane, Lorry Driver, from Nottingham, 51 Brecon Street. My story..." "Yes, What were you doing, Mr. Crane?" "Well, I had a breakdown yesterday and had to stay here until it was fixed. Bed and breakfast. The landlady is Mrs. Fern. She gave me breakfast at seven, and I was out here in the right way and down at the lorry park. It was only when I felt for a cigarette that I realised I'd left 80 pounds under the pillow. It's my habit to put my money under the pillow at night." "I see. Have you paid Mrs. Fern?" "I'd paid her last night. So I came back, but it's Sunday, and she'd gone back to bed. Could I wake her? I rang the bell and knocked on the door for ten minutes before I came here and found my bedroom window still open. Up I went, then, up this pipe. The money was still there. I hope you believe it because..." "Mr. Crane, what are you doing here? I thought you'd gone an hour ago." It was Mrs. Fern, speaking from the kitchen window.
Answer: He chose to go that way by chance.
Solution:
Why was Tidwell walking along the path behind Digby Hall Road?