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 CPP):

Solution:
/*
	0073:Surface Area of Quadrangular Pyramid
*/
#include	<iostream>
#include	<cstdio>
#include	<cmath>

using namespace std;

int main(void) {
	while(1) {
		int x, h;
		cin >> x >> h;
		
		if(x == 0 && h == 0) { break; }
		
		printf("%.6f\n", x * sqrt(4 * h * h + x * x) + x * x );
	}
}