Greeting Card

Quido is sending a new year greeting to his friend Hugo, and he prints the card on a high precision plotter.

The plotter works in two steps. First it plots a pattern of $n$ dots on the paper. Then it draws a straight segment between every pair of dots that lie exactly $2018$ length units apart.

The plotter prints with a special holographic ink that is in short supply, so Quido wants to know how many segments the picture contains before he starts the job.

The first line contains a positive integer $n$, the number of plotted points. Each of the next $n$ lines contains two space separated integers, the coordinates of one point. Every coordinate is non-negative and smaller than $2^{31}$. There are at most $10^5$ points and all of them are distinct.

All coordinates and distances are given in plotter length units, and one unit in the x direction has the same length as one unit in the y direction.

Print one integer, the number of pairs of points whose distance is exactly $2018$.