How do I increase the maximum file size for upload images in Event Manager

Hi.
I've installed events manager plugin.

The problem is that the maximum upload image size is too small for me, and I'd like to increase it

When I try to upload an event from the front end, It answer me:

The image file size is too big. The maximun size is 204800

You can check it on:

http://noticias.sinoduelenovale.com/eventos/

thanks