Surface Integrals, Stokes & Divergence · Easy problem

Let $\mathbf F = (-3y, 3x, z^2)$ and let $C$ be the circle $x^2 + y^2 = 1$ in the plane $z = 2$, oriented counterclockwise when viewed from above. Use Stokes' theorem to find $\oint_C \mathbf F\cdot d\mathbf r$. Give an exact answer in terms of $\pi$.