7841번 - Count Squares 다국어

문제

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

입력

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

출력

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

제한

• $-10^4 \le x_i, y_i \le 10^4,ドル 1ドル \le N \le 2000$.
• All points in the input are different.

힌트