Rotational Inertia

A large uniform solid disc has a mass of 50 kg with a 10 kg 0.75 m long uniform rod added radially from the dsics axis and extending to the outside edge of the disk. What is the rotational inertia of this system?

(I think that the discs rotational inertia is 1/2mR^2, and the uniform rod is 1/3ml^2)