If $$a = \frac{\sqrt{5} + 2}{\sqrt{5} - 2}$$ and $$b = \frac{\sqrt{5} - 2}{\sqrt{5} + 2}$$, then the value of $$2a^2 + 2b^2 - 5ab$$ is equal to:

A

693

B

649

C

635

D

639