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: Chuck sat at the bank of the river fishing. 
 Initial Context: He saw a duck swim nearby. 
 Original Ending: He tossed a piece of his sandwich bread to the duck. A minnow came up to nip at the bread, but was eaten by the duck. Chucked sighed that his new fishing buddy was catching more than him. 
 Counterfactual Context: He saw an alligator swim nearby.
Output:
He tossed a piece of bread away from him, and the alligator. A minnow came up the nip at the bread, the alligator at him. Chuck sighed, he wouldn't be able to catch anything this this alligator near by. 