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.

Examples