Best Sun

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문제

Ivan likes painting. He decided to paint a sun.

To do that, he took nn points with integer coordinates on the plane. Ivan will draw segments connecting some pairs of points to get the best sun.

  • Ivan will connect exactly nn pairs of points with segments between them.
  • All segments should not intersect (except for endpoints).
  • There should be exactly one cycle. This cycle should be a convex polygon.
  • Each point that is not one of the polygon vertices should lie outside of the polygon and should be connected with one of the polygon's vertices.
  • It is possible that all vertices will lie on the cycle.

Ivan wants to paint a bright, pretty sun. So he came up with the score of the sun:

  • Let us define SS as the area of the polygon.
  • Let us define PP as the sum of lengths of all drawn segments.
  • The value SP\displaystyle \frac{S}{P} is the score of the sun.

What is the maximum possible score of the sun?

입력

The first line contains a single integer tt (1t1041 \leq t \leq 10^4) --- the number of test cases. Description of test cases follows.

The first line of each test case contains a single integer nn (3n3003 \leq n \leq 300) --- the number of points.

Each of the next nn lines contains two integers x_ix\_i, y_iy\_i (x_i,y_i106|x\_i|, |y\_i| \leq 10^6). All points are different. No three points lie on the same line.

It is guaranteed that the sum of n2n^2 for all test cases does not exceed 90,00090\\,000.

출력

For each test case, print a single real number --- the maximum possible score of the sun that can be drawn.

The absolute or relative error should not exceed 10610^{-6}.

힌트

The picture of the sun with the maximum score in the fourth test case:

For this sun, S=64S = 64, P=32+45P = 32 + 4\sqrt{5}, so its score is 6432+45\displaystyle \frac{64}{32+4\sqrt{5}}.