I have a question about accessing elements in lists.

This is the code:

```
movies = ["The Holy Grail", 1975, "Terry Jones and Terry Gilliam", 91,
          ["Graham Champman", ["Michael Palin", "John Cleese", "Terry Gilliam", "Eric Idle", "Terry Jones"]]]

print(movies[4][1][3])

```

And this is the output: `Eric Idle`

My question is why is the output `Eric Idle`? What does `4` represent, what do `1` and `3` represent? I'm so confused.