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: When I was thirteen years old. 
 Initial Context: Me and my friends went for a fishing trip. 
 Original Ending: We fished all day. We caught salmon and trout. It was a magnificent sunny day. 
 New ending: We biked all day. We cycled hard and fast. It was a magnificent sunny day. 

SOLUTION: Me and my friends went for a biking trip.

PROBLEM: Premise: Anna was on a ship in the ocean. 
 Initial Context: She was watching the waves eagerly. 
 Original Ending: She hoped to see a mermaid! She tried to scan the entire ocean. But after weeks, she had not seen any mermaids. 
 New ending: Luckily, it was only a dream but she really wanto see a mermaid. She tried to scan the entire ocean. But after weeks, she had not seen any mermaids. 

SOLUTION: She fell into the water.

PROBLEM: Premise: Tim was a great driver. 
 Initial Context: His car was too slow. 
 Original Ending: He would often race his friend's car. He was known well at the quarter mile track. Tim eventually got his own fast car. 
 New ending: He would often race his friend's car. He was known well at the quarter mile track. Tim had the fastest car in town. 

SOLUTION:
His car was super fast.

