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: Rob had always wanted to join the Marines. 
 Initial Context: He knew it would be quite difficult, but believed in his dream. 
 Original Ending: He spent all his free time preparing and joined ROTC. When he turned 18, Rob immediately started the process of joining. He was never happier than on the day he completed training. 
 Counterfactual Context: He couldn't because of a heart condition.
Student:
He spent all his free time preparing and joined ROTC, but then was kicked out. When he turned 18, Rob immediately started working in an office. He was never happy. 