Curve attractor: defining biggest/smallest dimensions of an object

Hi,

I am a beginner at Rhino and Grasshopper and I have a question. Maybe it is not the most difficult thing, but i didn't managed to find a solution on the internet.

I managed to develop this script with help of tutorial. But I would like to define the smallest AND the biggest circle dimensions. How could I do it?

This this script now takes only one of those critical dimensions: biggest or smallest (depending on how I connect things), but not both.