Autonumbering with Headings

Hi,

I'm trying to auto number some of my headings. Ideally, I would like Heading 1 to have no auto numbering, Heading 2 to go by 1.1, 1.2, 2.1, 2.2, etc, and Heading 3 to go by 1.1.1, 1.1.2, 2.1.1, 2.1.2, etc.

Is there any way to achieve this without having to auto number Heading 1?

Thanks.