# Drunk

Time Limit: 1000MS

Memory Limit: 65535KB

## Description

Jenny is seriously drunk. He feels as if he is in an N-dimension Euclidean space, wandering aimlessly. In each step, he walks toward some direction and the “length” of each step will not exceed R. Technically speaking, Jenny is initially located at the origin of the N-dimension Euclidean space. Each step can be represented by a random N-dimension vector(x1, x2,..... ,xn) chosen uniformly from possible positions satisfying xi>=0 and x1^2 + x2^2 + ....<=R^2.

Assume the expectation of his coordinate after his first step is (y1, y2,......yn). He wants to know the minimum yi .

## Input

Each test case, only one line contains two integers N and R, representing the dimension of the space and the length limit of each step.(1<=n<=2

## Output

For each test case, print a real number representing the answer to the question above.

## Sample Input

2 1


## Sample Output

0.4244131816


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