Use the divergence theorem to evaluate $\iint_{S} \mathbf{F} \cdot d \mathbf{S}$ where $\mathbf{F}(x, y, z)=y^{2} z \mathbf{i}+y^{3} \mathbf{j}+x z \mathbf{k}$ and $S$ is the boundary of the cube defined by $-1 \leq x \leq 1,-1 \leq y \leq 1,$ and $0 \leq z \leq 2$.