Problems

# Surface area of pyramid 4

# Surface area of pyramid 4

Find the total surface area of the right square pyramid if the lateral edge **b** forms an angle **α** with the plane of the base.

**Input**

In the only flow through the gap two integers: the lateral edge of**b** (**0** < **b ≤ 100**) and its angle **α** with the base plane in degrees (**0** < **α**** ≤ 90**).

**Output**

The only number - the desired area. Result output to three decimal.

Input example #1

4 45

Output example #1

43.713