Given $n$ points, find the area of the largest quadrilateral formed by four arbitrary points in these points.
### Input
- The first lines contains an integer $n$.
- The next $n$ lines, each line contains a point $(x, y)$.
### Output
- Print the maximum area, rounded to **exactly** to one decimal places.
### Constraints
- $ 1 \le n \le 5000$.
- $-10^9 \le x, y \le 10^9$.
### Example
Input:
```
5
1 0
0 1
1 2
2 1
2 2
```
Output:
```
2.0
```
