TASK DEFINITION: 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: Brad wanted to learn Spanish. 
 Initial Context: He decided to take a Spanish class. 
 Original Ending: He practiced the language diligently every day. By the end of the class, he was speaking Spanish fluently. Brad was proud that he accomplished his goal. 
 New ending: He practiced the language diligently every day. By the end of the class, he was speaking Mandarin fluently. Brad was proud that he accomplished his goal. 

SOLUTION: He decided to take a Mandarin class.

PROBLEM: Premise: Bob the theater manager was expecting a big crowd at the show. 
 Initial Context: He took out extra chairs from storage and placed them in the rear. 
 Original Ending: When the show started he still needed more seating. The manager had to explain to the patrons that they had to stand. The patrons tried to find a spot on the wall to lean against. 
 New ending: When the show started, no one needed more seating. The manager had to explain to the patrons why there were extra chairs. The patrons did not have trouble finding a spot to sit. 

SOLUTION: However he was disappointed when ever it was time for the show.

PROBLEM: Premise: I challenged Rachel to a race. 
 Initial Context: The race was 50 meters long. 
 Original Ending: She accepted and we took off. Rachel beat me. I am so embarrassed, I need to practice for next time. 
 New ending: She accepted defeat. Rachel didn't beat me. She is so embarrassed, she needs to practice for next time. 

SOLUTION:
The race was 50 meters long and I won.

