Teacher:Given a premise, an initial context, an original ending, and a counterfactual context, the task is to generate a new story ending aligned with the counterfactual context and as close to the original ending as possible. 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 and the story's general plot. The original ending is the last three sentences of the story. Also, a counterfactual context is a slight modification to the initial context. You should write a new story ending that edits the original story ending as little as possible to regain coherence with the counterfactual context. To sum up, you should write the last three sentences of a story based on the premise(first sentence) and the counterfactual context(second sentence) of the story.
Teacher: Now, understand the problem? Solve this instance: Premise: Johnny went surfing this weekend alone. 
 Initial Context: He knows you shouldn't surf alone, but he still went. 
 Original Ending: Johnny was having a lot of fun, until he saw a fin. He knew it was a shark, and started to paddle. He made it to the shore, looked back to see it was only a dolphin. 
 Counterfactual Context: Luckily, he didn't see any sharks while surfing alone.
Student:
Johnny was having a lot of fun, until he saw a person floating. He knew it was a drowned person, and started to paddle. He made it to the person. 