New to CI - have small question...

[eluser]bookworm[/eluser]
Hello there. I'm trying to choose a suitable framework to use in my projects.
So would you please give me an answer to next question: is it possible in CI to set a controller for any url which doesn't have a controller? Sorry for my English, I'll try to explain...

1. I have a tree structure of pages (site's content)
e.g.
"/mytopic1/mypage1"
"/mytopic1/mypage2"
"/mytopic2/mypage1"
"/mytopic3"
2. I have some content of another type
"/news"
"/polls"

So. I want to have 3 controlles: news.php, votes.php and other_pages.php
The last one is for my content tree.

Is it possible in CI? Is it flexible enough?
Or maybe I should use something like 404-error-controller?

I really don't want to have these urls:
mysqsite.com/pages/mytopic1/mypage1
mysqsite.com/pages/mytopic2/mypage2
mysqsite.com/news
mysqsite.com/votes

I need this style:

mysqsite.com/mytopic1/mypage1
mysqsite.com/mytopic2/mypage2
mysqsite.com/news
mysqsite.com/votes