Definition: In this task, you're given an article and an answer. Your task is to generate the fill-in-the-blank question for this answer based on the given article. The blanks are always at the end of the question, and can be filled with more than one word or phrase.
Input: Article: Once a great boxer  , Tom Brown, went to a restaurant for dinner. He put his bag near the door, but he was afraid that someone would take it. So he got out a pen and a piece of paper and wrote on it: "The great boxer, Tom Brown, left his bag here. He'll come back in a few minutes. " He put the paper on his bag and went to have his dinner. When he came back, his bag wasn't there. But he found a piece of paper on the ground. It said: "A great runner took away your bag, and he will not come back. " 
 Answer: for his pen
