## 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```

## Code Examples

### #1 Code Example with Python Programming

```Code - Python Programming```

``````import math

while True:
l = float(input())
if l == 0:
break
print('%.2f' %(l * l / math.pi / 2))``````
Copy The Code &

Input

cmd
1
0

Output

cmd
0.16

### #2 Code Example with C++ Programming

```Code - C++ Programming```

``````#include <iostream>
#include <stdio.h>
#include <iomanip>
using namespace std;

int main() {
int l;
while(cin>>l){
if(l==0)
break;
double res=(l*l)/(2*3.14);
cout << fixed << setprecision(2) << res <<endl;
}
return 0;
}``````
Copy The Code &

Input

cmd
1
0

Output

cmd
0.16

## Demonstration

SPOJ Solution-Build a Fence-Solution in C, C++, Java, Python