Need help with ankle

I posted on the S/C forum and got some help but not a lot. I just had two screws put threw my ankle and am now getting to walk some in a walking cast. I was wondering if someone could help with exercises I could possibly due to start building strength in my ankle and calf. My left calf is about an inch smaller due to lack of use. I can't spend a lot of time on the ankle yet but some sort of exercise would be good.
Thanks