Evaluate the circulation of $\vec{G} = xy \vec{i} + z\vec{j} + 3 y\vec{k}$ around a square of side $7$, centered at the origin, lying in the yz-plane, and oriented counterclockwise when viewed from the positive x-axis.

Circulation = $\displaystyle \int_C \vec{F} \cdot d\vec{r}$ =