题目描述

小青遇到了这样一个问题：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.

输入格式

The first line of the input contains the number of test cases in the file. And t he first line of each case contains one integer numbers n(0<n<30) specifying the number of the point . The n next n line s, each line contain s Three Integer Numbers xi,yi and zi, indicating the position of point i.

输出格式

For each test case, output a line with the answer, which should accurately rounded to two decimals . 2 2 1 1 0 2 2 0 3 1 2 3 0 0 0 1 1 1

样例

样例 1

输入 # 1

2

2

1 1 0

2 2 0

3

1 2 3

0 0 0

1 1 1

输出 # 1

1.41

3.97