Surface Integrals, Stokes & Divergence · Superchallenge problem

Let $S$ be the sphere $x^2 + y^2 + z^2 = 4$. Compute $\displaystyle\iint_S \frac{dS}{\sqrt{(x - 1)^2 + (y - 2)^2 + (z - 2)^2}}$. Give an exact answer in terms of $\pi$.