UNIR  Universal Radius
Given two point A and B that center of two circle. The two circle are equal and tangent externally. you have to find the radius that are equal of both circle radius. See the picture below :
Input
Input starts with an integer T ( ≤ 250 ), denoting the number of test cases. Each case contain four integers x_{1}, y_{1}, x_{2}, y_{2} (10^{6} ≤ x_{1}, y_{1}, x_{2}, y_{2} ≤ 10^{6}) where x_{1} and y_{1} are coordinates of the first point and x_{2} and y_{2} are coordinates of the second point. It's guaranteed that the given points are distinct.
Output
For each case, print the answer to the problem which describe above. Answer round with 6 decimal places.
Example
Input:2
0 1 5 10
2 1 4 9Output:
5.147815
4.123106
Problem setter: Shipu Ahamed, Dept. of CSE
Bangladesh University of Business and Technology (BUBT)
hide comments
nadstratosfer:
20180820 08:09:29
No floats in input, my code was designed to crash if it was otherwise but got AC. 

wisfaq:
20141018 19:11:45
Please add that the answer must be rounded to 6 places after the decimal point.


ivar.raknahs:
20141018 19:11:45
Wrong input declaration . Inputs are in float.


mehrab alam:
20141018 19:11:45
@Shipu Ahamed correct input statement inputs are in floats


Wonderwice Margera:
20141018 19:11:45
For fun, we should change it to a challenge problem with score = number of characters in answer. Last edit: 20140915 11:32:42 

Ayush Agarwal:
20141018 19:11:45
In the problem it's mentioned the coordinates of the two centers will integers, but in the test cases, there are non integral coordinates too!!! Last edit: 20140915 10:56:17 

Raghav Aggiwal:
20141018 19:11:45
Piece of cake !! 

Shipu Ahamed:
20141018 19:11:45
@Ayush Agarwal : Find out by yourself... 
Added by:  Shipu Ahamed 
Date:  20140914 
Time limit:  1s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ASM64 