Lines & Planes in Space · Challenge problem

The lines $\mathbf r_1(t) = (1, 2, 0) + t\langle 1, 0, 1\rangle$ and $\mathbf r_2(s) = (0, 1, 3) + s\langle 0, 1, -1\rangle$ are skew. There is exactly one plane that is parallel to both lines and equidistant from them. Find the distance from the origin to this plane.