I'm on the record in a publication a couple of months ago as saying that when you do the math, and going back to the rule of three or four, I believe we need at least three submarines available to us at any point in time. That could be geographically logical, with one on each coast. In order to maintain that, we're going to need roughly three times that number, so we're looking at nine. That probably means that we're looking at, I would suggest, 10 as probably not a bad number.
That is an unsophisticated rough calculation. I look forward to hearing what the navy thinks.