Evaluate the surface integral $\int_S \mathbf{F} \cdot \ d \mathbf{S}$ where $\mathbf{F}=\left< 2 x, z, - y \right>$ and $S$ is the part of the sphere $x^2+y^2+z^2=16$ in the first octant, with orientation toward the origin.

$\int\int_S \mathbf{F} \cdot \ d \mathbf{S}=$