Cycling through tiled windows

Okay, probably a very dumb question here.  If I split a screen into
three tiled windows, such as:

___________________________
|                               |                             |
|                               |              B            |
|                               |                             |
|              A               | ____________|
|                               |                             |
|                               |               C           |
|                               |                             |
| _____________|____________ |

How can I cycle focus among all three windows using the keyboard?  I
can Alt-Tab (actually Super-Tab on my box) from left to right, which
would be like A -> B and B -> A, but I cannot move from B -> C or
vice-versa.  To do that I have to use the mouse, which is obviously
less than desirable.  I have read through the docs and the config
files hoping to see something which may relate to this in the
bindings, but there seems to be nothing there beyond the side to side
action.

Surely this is possible, but for some reason I am overlooking it.  How
exactly would I manage to cycle through all three of these windows?

Patrick