Instructions: In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.
Input: Passage: The story begins with a farm mother scolding Jack for trading his cow for five seemingly worthless beans. The beans are thrown out a window and land under Sylvester's cat bed while the lazy cat is taking a "catnap". Instantly, the beans sprout into a giant beanstalk that reaches into the heavens, taking the still sleeping Sylvester with it. The puddy tat awakens and is startled at how everything seemingly grew overnight. Eventually, he walks inside a castle and instantly spots a giant birdcage (with a giant Tweety singing inside). Sylvester opens the cage and chases what he says are "acres and acres of Tweety Bird." However, Tweety's master comes into the room; after Sylvester hides, the master puts Tweety back in his cage and hangs it on a high ceiling; that way, he will not get into any mischief while he is gone.
Sylvester makes several attempts to get at Tweety, having to overcome both the cage being on the ceiling and dodging a giant bulldog who is trying to chase the cat away. Each of Sylvester's attempts to get the bird ends unsuccessfully; several times, he is barely able to get away from the bulldog. At one point, he encounters a real giant mouse, only to have both of them get scared of each other and run away in opposite directions.
Output:
What is the name of the character who enters a castle and finds a giant birdcage?