Problem: 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

Solution (in PYTHON3):

Solution:
# AOJ 0073: Surface Area of Quadrangular Pyramid
# Python3 2018.6.15 bal4u

import math
while True:
	x = int(input())
	if x < 1: break
	h = int(input())
	s = math.sqrt(4*h*h + x*x) + x;
	print(s*x);