FENCE1 - Build a Fence

There is a wall in your backyard. It is so long that you can’t see its endpoints. You want to build a fence of length L such that the area enclosed between the wall and the fence is maximized. The fence can be of arbitrary shape, but only its two endpoints may touch the wall.

Input

The input consists of several test cases.

For every test case, there is only one integer L (1<=L<=100), indicating the length of the fence.

The input ends with L=0.

Output

For each test case, output one line containing the largest area. Your answer should be rounded to 2 digits after the decimal point.

Example

Input:
1
0

Output:
0.16

Added by:Fudan University Problem Setters
Date:2009-05-23
Time limit:1s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: C99 ERL JS-RHINO NODEJS PERL6 VB.NET
Resource:Fudan University Local Contest #1, practise session

hide comments
2017-02-12 21:20:33
2 WA, because I used 22/7.
2017-02-06 20:46:19
AC in one go :-)
2017-01-16 16:32:03
Don't use round() in python instead of %.2f
2017-01-01 12:51:57
ac in one go......
2016-12-22 17:21:16
Do not use 22/7 as the value of pi
instead use 3.14159
2016-11-17 18:47:05
My 50th and yeah i got 2 wa just coz i forgot to write \n in cpp ,,nd thats why i hate cpp nd c -_-
Also circle is the shape which has max area and rectangle has max perimeter i guess...school maths :P :P
And in this case we need to draw a semi circle... :)
2016-11-04 07:35:22
can anyone please explain why Length=Radius*PI ? I got the problem statement,And how to do that.But this one is till now confusing to me :)
2016-11-01 10:53:45
use pi as 3.14159, float works!!!!
2016-10-31 17:31:49
typecasting errors can occur ... use everything in double
2016-09-24 20:07:18
Don't use 22/7 as the value of pi gives WA
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