p00073 Surface Area of Quadrangular Pyramid
Create a program that outputs the surface area S of a square cone with a height of h, with a square with one side x as the base. However, assume that the line segment connecting the apex and the center of the base is orthogonal to the base. Also, x and h are positive integers less than or equal to 100.

Input

Given multiple datasets. Each dataset is given in the following format:


x
h


When both x and h are 0, it indicates the end of input.



Output

Output S (real number) on one line for each data set. The output may contain an error of 0.00001 or less.

Example

Input

6
4
7
9
0
0


Output

96.000000
184.192455
```python
from math import sqrt
while True:
    x, h = int(input()), int(input())
    if x==h==0: break
    sh = sqrt((x/2)**2 + h**2)
    print((x*x) + sum([sh*x*0.5 for _ in range(4)]))
```