ElectroMagentic Field

Consider two spherical metal shells of radii $a$ and $b$ . There is a magnetic dipole of moment $M$ in the center of the inner sphere. There is a charge $+q$ on the inner sphere and $-q$ on the outer sphere.Find the $\vec{L}$ angular momentum associated with the electromagnetic field of the system. If your answer comes in the form $L=\frac{\alpha qM}{\beta c}(\frac{1}{a}-\frac{1}{b})$ Type your answer as $\alpha+\beta$