Problems
The surface area of the cone
The surface area of the cone
Calculate the total surface area of a truncated cone, if we know the base radius \textbf{R}, \textbf{r} and height \textbf{h}.
\InputFile
In a single line of succession through a gap defined, respectively, the base radius \textbf{R}, \textbf{r} and height \textbf{h}. All input data are integers, not exceeding \textbf{100}.
\OutputFile
In a single line to bring the total surface area of a truncated cone. Result output to two decimal places.
Input example #1
4 3 5
Output example #1
190.67