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문제

There are n distinct points in the plane, given by their integer coordinates. Find the number of parallelograms whose vertices lie on these points. In other words, find the number of 4-element subsets of these points that can be written as {A, B, C, D} such that AB || CD, and BC || AD. No four points are in a straight line. 

 

입력

The first line of the input file contains a single integer t (1 ≤ t ≤ 10), the number of test cases. It is followed by the input data for each test case.
The first line of each test case contains an integer n (1 ≤ n ≤ 1000). Each of the next n lines, contains 2 space-separated integers x and y (the coordinates of a point) with magnitude (absolute value) of no more than 1000000000.

 

출력

  • Output should contain t lines.
  • Line i contains an integer showing the number of the parallelograms as described above for test case i.

 

예제 입력

2
6
0 0
2 0
4 0
1 1
3 1
5 1
7
-2 -1
8 9
5 7
1 1
4 8
2 0
9 8

예제 출력

5
6

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