Count Squares

Given a set of points with integer coordinates x_i, y_i, i = 1...N, your program must find all the squares having each of four vertices in one of these points.

Input file contains integer N followed by N pairs of integers x_i y_i.

Constraints

-10⁴ ≤ x_i, y_i ≤ 10⁴, 1 ≤ N ≤ 2000. All points in the input are different.

Output file must contain a single integer — number of squares found.

<b>Sample input 1</b>
4 0 0 4 3 -3 4 1 7
<b>Sample input 2</b>
9
1 1  1 2  1 3  
2 1  2 2  2 3  
3 1  3 2  3 3

<b>Sample output 1</b>
1
<b>Sample output 2</b>
6

Bold texts appearing in the sample sections are informative and do not form part of the actual data.