Given the task definition and input, reply with output. In this task, you're given a four sentences of story written in natural language. Your job is to complete end part of the story by predicting appropriate last sentence which is coherent with the given sentences.

Sentence1: Alec kept waking up with pain in his stomach. Sentence2: He realized that he needed to change his diet. Sentence3: At first it was really hard to change his eating habits. Sentence4: He came up with a reward system.
With that in place, he did alright.