Detailed Instructions: Given a premise, an initial context, an original ending, and a new ending, the task is to generate the counterfactual context that is aligned with the new ending. Each instance consists of a five-sentence story. The premise is the first sentence of a story, and the second sentence, which is the initial context, provides more information about the story's context. The original ending is the last three sentences of the story. Also, you are given a new ending that can provide the new story with the same premise. You should write a counterfactual context to explain the small differences between the original and new endings. More specifically, a story context contains the general plot of the story. And a counterfactual context is a slight modification to the initial context. To sum up, you should write the second sentence of a story based on the premise(first sentence) and the new ending(last three sentences) of the story.
Problem:Premise: Mark was an American spy during the Cold War. 
 Initial Context: He was told to steal a document from the Russians in Berlin. 
 Original Ending: At night, he snuck up to the hidden building. A guard heard him, but did not see him sneaking inside. Mark stole the document and escaped easily. 
 New ending: In the morning, he walked up to the hidden building. A guard heard him, and saw him walking inside. Mark bought the document and left easily. 
Solution:
He was told to buy a document from the Russians in Berlin.