Given N points on plane, the N points forms a convex polygon. You need to find M points among them, then we calculate the convex hull of the M points.
You need to maximize The area of the convex hullThe perimeter of the convex hull.
Input Format
First line contains two integers N,M(2≤M≤N≤120).
Each of the next N lines contains two integers Xi,Yi(−109≤Xi,Yi≤109), represent a point.
It's guaranteed no two points coincide.
Output Format
One float number, represent the answer, round to 4 decimal digits. It's guaranteed the output will not change if we add 10−6 to the answer or subtract 10−6 from the answer.
Note : The statement for this problem has been updated. We are rejudging all submissions, please check announcement on contest page for detailed issue.
The sample is in the above graph. Area=3,Perimeter≈7.300563.
