An input device includes a sensor configured to generate a signal related
to a change in inertia around at least one axis of the input device in
response to a contacting of the input device. A processor is configured
to receive the signal from the sensor to determine whether the change in
inertia around the at least one axis of the input device corresponds to a
tapping of the input device. The processor is further configured to
identify a contacted region of the input device based on a direction of
the change in inertia around the at least one axis of the input device
when the change in inertia corresponds to a tapping of the input device