A unit vector making an obtuse angle with the x-axis and perpendicular to the plane containing the points $\hat{i} + 2\hat{j} + 3\hat{k}$, $2\hat{i} + 3\hat{j} + 4\hat{k}$, and $\hat{i} + 5\hat{j} + 7\hat{k}$ also makes an obtuse angle with which axis?