Number one question, number two is Y v a large positive or is Y v a large negative for a typical ship, we will find how that, regardless of ship some of the numbers are always large, some of the number are always negative, some of the number are always positive regardless of what the ship is? Because, if that is the case like, if you can find out then you can actually use that to this stability derivative, because this B and A as you know are long terms this B equal to A 1 B 2 minus etcetera; and A 1 B 2 each one of them is again long derivative, so this turns out to be a large number of derivatives.