And then if it's the other way around, if d of three is greater than r of three, then water in pipe decreasing. Then you're draining faster than you're putting into it. Then water in pipe decreasing. So we just have to evaluate these functions at three. So let's see, r, actually I can do it right over here. So let me make a little line here. So r of three is equal to, well let me get my calculator out, this is going to be, oops, not that calculator, let me get this calculator out.