Definition: 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.
Input: Premise: Sasha wanted a unicorn for Christmas. 
 Initial Context: She had a pet horse in the stable. 
 Original Ending: Sasha wanted one with a pretty horn on its head. She begged her mom all day before Christmas. Sasha woke up to her horse having a horn taped to its temple. 
 Counterfactual Context: Her mom told her that unicorns dont exist.
Output:
She didn't believe her and wanted a horse with a pretty horn on its head She begged her mom all day before Christmas Sasha woke up to her horse having a horn taped to its temple 