Pure comparative negligence with J+S

[waxecstatic]

Hey, I was wondering if someone could explain how this works for me. If you're in comparative negligence jurisdiction, then as a plaintiff, your award is deducted by the percentage of your fault. If a jurisdiction retains J+S liability, then does this mean you can choose how much you want from each of the remaining defendants, as long as it does not exceed their liability? I'm a little confused how to explain this so I'll throw out an example.

Assume A is 20% at fault for an accident, and there are 2 other tortfeasors, B, and C. A's damages are $1,000,000.

B=15%
C=65%


How much could A recover from B?

Thanks!!