N points are placed in the coordinate plane. Write a program which calculates in how many ways a right triangle can be formed by three of the given points. A right triangle is one in which one of the angles is 90 degrees.

Input

The first line of input contains an integer N (3 <= N <= 1500), the number of points. Each of the following N lines contains the coordinates of one point, two integers separated by a space. The coordinates will be between -10^9 and 10^9. No two points will be located at the same coordinates.

Output

Output the number of right triangles. 

Sample

Sample input
 
input 
 
5 
-1 1 
-1 0 
0 0 
1 0 
1 1 
 
output 
 
7 

input 
 
4 
5 0 
2 6 
8 6 
5 7 
 
output 
 
0