3011：Cut Pyramid

Yaya and maomao have a cake. And the shape of the cake is a pyramid. As the following picture, AB=AC=AD=BC=BD=CD=N. Now they want to cut the cake to two same volume pieces as following picture. And EF is on the plane BCD and parallel to CD. GH is on the plane ACD and parallel to CD, too. Now give you the length of CE=L, and ask you to calculate the length of AG.

Input contains multiple cases each presented on a separate line. Each line contains two integer numbers N(5<=N<=1000),L (0<=L<=N).

For each test case, your program should output the length of AG hold 2 digits after the decimal point. If the answer is absent, output “Oh, my god!”.