In this task, you're given a context passage, followed by a question that needs to be answered. Based on the paragraph, you must write unambiguous answers to the questions and your answer must refer to a specific phrase from the paragraph. If multiple answers seem to exist, write the answer that is the most plausible.

Let me give you an example: Tracy slept awkwardly on their new bed and was having some pain, so Tracy cracked her neck.
Question: What did Tracy do with her neck?
The answer to this example can be: crack her neck
Here is why: The output phrase perfectly answers the question and is explicitly mentioned in the passage as well.

OK. solve this:
One of the buttons came off on my shirt, so I have to sew it back on. Sewing a button can be tricky, since you need a very steady hand. I get some thread and a sewing needle and get to work. I carefully put the button on my shirt, and start sewing. I tie a knot on the end of my thread, and put the needle through the underside of my shirt to where the button is. I guide the needle from under the shirt through one of the holes in the button, and then back through another hole. I do this many times, alternating between the four holes to make sure the button's on tight. There are a lot of ways you can sew a button, but I like to do it so the stitch looks like an X. Once I've done it enough times, I can tie off my thread and my button's as good as new!
Question: When did they stop sewing the button?
Answer:
after sew tightly