Points

There are $n + m$ points on the plane. Exactly $n$ of them are white and the remaining $m$ are black.

Count the number of triangles whose three vertices are white points and that contain no black point in their interior.

You may assume that no three points are collinear.

The first line contains two integers $n$ and $m$ ($0 \le n, m \le 500$), the number of white points and the number of black points, respectively.

The next $n$ lines describe the white points, and the following $m$ lines describe the black points. Each line contains two integers $x$ and $y$ ($-10^9 \le x, y \le 10^9$), the coordinates of a point.

Print, on a single line, the number of triangles with white vertices that contain no black point inside.

The figure above illustrates the first example.