Triangles#239
points are given on the plane with integer coordinates. No three points lie on one line. Find , the number of triangles with vertices at these points and integer area.
The first line contains . Each of the next lines contains two integers x_i, y_i, the coordinates of the next point. It is known that 0 < n, |x_i|, |y_i| \leq 5000.
Print , the answer.
Example 1