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: Roger was hiking in the mountains. 
 Initial Context: He came upon a flock of birds. 
 Original Ending: The flock of birds chased Roger to the edge of the mountain. Luckily, Roger evaded the birds before he had to jump off the cliff. Roger decided to never go back to that mountain. 
 Counterfactual Context: He came upon a few songbirds.
Output:
The flock of birds were very aggressive and chased Roger to the edge of the mountain. Luckily, Roger evaded the birds before he had to jump off the cliff. Roger decided to never go back to that mountain. 