Triangles
The novel has long been involved enough in the mathematical circle, so he managed to learn not only the rules of simple operations, but also on such a fairly complex concept as symmetry. A good way to explore symmetry, Roman decided to start with the most simple geometric shapes - triangles. He soon realized that the axial symmetry have the so-called isosceles triangles. Recall that the triangle is isosceles if its area is positive, and he has at least two equal sides.
Recently, novel, going to class, I saw that on a board drawn n points. Of course, he immediately thought, as there are triples of the points which are vertices of isosceles triangles.
Need to write a program that solves these problems.
Input
The input file contains the first line of an integer n (3 ≤ n ≤ 1500). Each subsequent row contains two integers separated by a space – x_i and y_i, determining the coordinates of the i i-th point. All the coordinates of points does not exceed 10^9 in absolute value. Among the data points do not coincide.
Output
In the output file should display the answer to the above tasks.