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A MST Problem 1095

Description

It is just a mining spanning tree ( 最小生成树 ) problem, what makes you a little difficult is that you are in a 3D space.

Input

The first line of the input contains the number of test cases in the file. And the first line of each case contains one integer numbers n (0<n<30) specifying the number of the point . The next n lines, each line contains Three Integer Numbers x_i, y_i and z_i, indicating the position of point i.

Output

For each test case, output a line with the answer, which should accurately rounded to two decimals .

Samples