Nikon SLR Cameras

What size of UV filters do I need for these two lenses?

Snakes on a plane
Snakes on a plane

Nikon 50mm f/1.8D AF Nikkor Lens (http://www.amazon.com/gp/product/B00005LEN4/sr=1-1/qid=1321312890/
and 18-55mm f/3.5-5.6 AF-S DX VR Nikkor Zoom Lens (http://www.amazon.com/Nikon-18-55mm-3-5-5-6G-AF-S-Nikkor/dp/B000ZMCILW/

Stephen Cheatley
Stephen Cheatley

Both 52mm.