Now our heroes -- Alakbar, Hidayet, Khayyam are working for SOCAR(State Oil Company of Azerbaijan Republic) as developers. Now they have faced a great problem. They couldn’t find the correct solution. Because the problem is related to math. Their friend Kamran can solve that problem. But he is working for Yandex. So he is not in Azerbaijan and our heroes can’t contact with him at this moment. Could you help them? We are given \textbf{r} -- radius of lower base and \textbf{s} -- slant height. The figure can be cylinder or truncated cone. You have to find as largest volume as possible to carry oil respect to given information. \includegraphics{https://static.e-olymp.com/content/90/9084b12702cfb29473a4e50aa9457739ff251d56.jpg} \InputFile You are given two numbers that less than \textbf{100}: radius \textbf{r} of lower base and slant height \textbf{s}. The slant height is the shortest possible distance between the edges of two bases. \OutputFile Print the largest volume with two digits after the decimal point.