Diamond Miner

Description:

Input:

The input consists of multiple test cases. The first line contains a single integer $$$t$$$ ($$$1\le t\le 10$$$) — the number of test cases. The description of the test cases follows.

The first line of each test case contains a single integer $$$n$$$ ($$$1 \le n \le 10^5$$$) — the number of miners and mines.

Each of the next $$$2n$$$ lines contains two space-separated integers $$$x$$$ ($$$-10^8 \le x \le 10^8$$$) and $$$y$$$ ($$$-10^8 \le y \le 10^8$$$), which represent the point $$$(x,y)$$$ to describe a miner's or a diamond mine's position. Either $$$x = 0$$$, meaning there is a miner at the point $$$(0, y)$$$, or $$$y = 0$$$, meaning there is a diamond mine at the point $$$(x, 0)$$$. There can be multiple miners or diamond mines at the same point.

It is guaranteed that no point is at the origin. It is guaranteed that the number of points on the x-axis is equal to $$$n$$$ and the number of points on the y-axis is equal to $$$n$$$.

It's guaranteed that the sum of $$$n$$$ for all test cases does not exceed $$$10^5$$$.

Output:

For each test case, print a single real number — the minimal sum of energy that should be spent.

Your answer is considered correct if its absolute or relative error does not exceed $$$10^{-9}$$$.

Formally, let your answer be $$$a$$$, and the jury's answer be $$$b$$$. Your answer is accepted if and only if $$$\frac{|a - b|}{\max{(1, |b|)}} \le 10^{-9}$$$.

Sample Input:

3
2
0 1
1 0
0 -1
-2 0
4
1 0
3 0
-5 0
6 0
0 3
0 1
0 2
0 4
5
3 0
0 4
0 -3
4 0
2 0
1 0
-3 0
0 -10
0 -2
0 -10

Sample Output:

3.650281539872885
18.061819283610362
32.052255376143336

Note:

In the first test case, the miners are at $$$(0,1)$$$ and $$$(0,-1)$$$, while the diamond mines are at $$$(1,0)$$$ and $$$(-2,0)$$$. If you arrange the miners to get the diamond mines in the way, shown in the picture, you can get the sum of the energy $$$\sqrt2 + \sqrt5$$$.