Problem S: A Sign In Problem

Problem S: A Sign In Problem

Time Limit: 1 Sec  Memory Limit: 128 MB
Submit: 6  Solved: 3
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Description

There are \(n\) points in a two dimensions area. You can choose at most four points to enclose this area. Please output the maximum area that can be enclosed.


Input


The first line is the integer n \(( 2 \leq n \leq 3000 )\).


The following n lines each line contains 2 number \(x_i,y_i\) \((-600000 \leq x_i,y_i \leq 600000, 1 \leq i \leq n)\).


Output

One line a number, representing the maximum area. Keep the result to one decimal place.


Sample Input

4
1.0 2.0
1.0 1.0
2.0 1.0
2.0 2.0

Sample Output

1.0

HINT

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