Lines & Planes in Space · Superchallenge problem

Line $L_1$ is the intersection of the planes $x + y + 2z = 4$ and $x + 2z = -2$. Line $L_2$ is the intersection of the planes $y + 2z = 2$ and $2x - 2y + z = 1$. Find the distance between $L_1$ and $L_2$.