Submission of Project 01

The pattern I like for this sort of thing is:
```python
non_activity_words = set(location_words + needy_words + others)
full_list = filter(lambda x: x not in non_activity_words, full_list)
```

In your version, words in `non_activity_words` turn into `None` whereas in my version they're removed. I think that's ok for what you're doing here.