Cylinder volume
A cylinder has a height h and a radius r. Your task is to calculate the volume of that cylinder.
As a reminder, the volume of the cylinder is calculated by multiplying the area of the base circle by the height:

The first 2 lines of the input are two floating-point numbers - the h and the r of the cylinder. 
Print its volume in the output.
Input  | Output  | 
|---|---|
15  | 1696.46  | 
Note: You can use math.pi for .
Constraints
Time limit: 2 seconds
Memory limit: 512 MB
Output limit: 1 MB