You will be given a definition of a task first, then some input of the task.
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.

Premise: Pharmasset was a biotechnology company in New Jersey. 
 Initial Context: The company was working on drugs to treat viral infections. 
 Original Ending: One of their drugs had great promise to cure patients of hepatitis B. A larger company, Gilead, bought Pharmasset for that drug. Now Gilead sells billions of dollars of the drug every quarter. 
 Counterfactual Context: The company was working on drugs to treat viral infections but Gilead will never sell billions of dollars of any drug.
Output:
One of their drugs had great promise to cure patients of hepatitis B. A larger company, Gilead, bought Pharmasset for that drug. Now Gilead gives away billions of dollars of the drug every quarter. 