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 **R**, **r** and height **h**.

**Input**

In a single line of succession through a gap defined, respectively, the base radius **R**, **r** and height **h**. All input data are integers, not exceeding **100**.

**Output**

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