CF1886B Fear of the Dark

Description

Monocarp tries to get home from work. He is currently at the point $ O = (0, 0) $ of a two-dimensional plane; his house is at the point $ P = (P_x, P_y) $ . Unfortunately, it is late in the evening, so it is very dark. Monocarp is afraid of the darkness. He would like to go home along a path illuminated by something. Thankfully, there are two lanterns, located in the points $ A = (A_x, A_y) $ and $ B = (B_x, B_y) $ . You can choose any non-negative number $ w $ and set the power of both lanterns to $ w $ . If a lantern's power is set to $ w $ , it illuminates a circle of radius $ w $ centered at the lantern location (including the borders of the circle). You have to choose the minimum non-negative value $ w $ for the power of the lanterns in such a way that there is a path from the point $ O $ to the point $ P $ which is completely illuminated. You may assume that the lanterns don't interfere with Monocarp's movement. ![](https://cdn.luogu.com.cn/upload/vjudge_pic/CF1886B/e2035d6f1a8a294e1d7b18148024db80f9680a4a.png) The picture for the first two test cases

Input Format

The first line of the input contains one integer $ t $ ( $ 1 \le t \le 10^4 $ ) — the number of test cases. Each test case consists of three lines: - the first line contains two integers $ P_x $ and $ P_y $ ( $ -10^3 \le P_x, P_y \le 10^3 $ ) — the location of Monocarp's house; - the second line contains two integers $ A_x $ and $ A_y $ ( $ -10^3 \le A_x, A_y \le 10^3 $ ) — the location of the first lantern; - the third line contains two integers $ B_x $ and $ B_y $ ( $ -10^3 \le B_x, B_y \le 10^3 $ ) — the location of the second lantern. Additional constraint on the input: - in each test case, the points $ O $ , $ P $ , $ A $ and $ B $ are different from each other.

Output Format

For each test case, print the answer on a separate line — one real number equal to the minimum value of $ w $ such that there is a completely illuminated path from the point $ O $ to the point $ P $ . Your answer will be considered correct if its absolute or relative error does not exceed $ 10^{-6} $ — formally, if your answer is $ a $ , and the jury's answer is $ b $ , your answer will be accepted if $ \dfrac{|a - b|}{\max(1, b)} \le 10^{-6} $ .