Given the task definition and input, reply with output. In this task, you're given a story (which contains five sentences only). Your task is to find all the characters which are available in the given story.

Sentence1: Brad build a bomb shelter when the war broke out. Sentence2: The war was never serious and eventually the tension ceased. Sentence3: Brad felt like he wasted his time on the shelter. Sentence4: The next week scientists said a meteor was headed to earth. Sentence5: Brad felt like luck was on his side.
Scientists, Brad