Given two points A and B that are the center of two circle. The two circle are equal is size and tangent externally. you have to find the radius of the circles. See the picture below:

Input

Input starts with an integer T (≤ 250), denoting the number of test cases. Each case contain four integers x₁, y₁, x₂, y₂ (-10⁶ ≤ x₁, y₁, x₂, y₂ ≤ 10⁶) where x₁ and y₁ are coordinates of the first point and x₂ and y₂ are coordinates of the second point. It is 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 -9

Output:
5.147815
4.123106

Problem setter: Shipu Ahamed, Dept. of CSE Bangladesh University of Business and Technology (BUBT)