Reflected inertia through a gear reduction

A revolute joint is actuated by an electric motor with rotor inertia $I_m = 0.5\times10^{-4}\ \text{kg·m}^2$, driving the link through an ideal (lossless, rigid) gearbox with reduction ratio $N = 100$ (motor turns 100 times per output revolution). The link-side load inertia (link plus payload, about the joint axis) is $I_L = 1.2\ \text{kg·m}^2$.

Neglecting gravity and friction, what is the total effective inertia the motor 'feels' at its own shaft (rotor inertia plus the load inertia reflected through the gearbox)?