Triangles

Description:

Input:

The first line contains two non-negative integer numbers N and M (0 ≤ N ≤ 500, 0 ≤ M ≤ 500) — the number of red and blue points respectively. The following N lines contain two integer numbers each — coordinates of red points. The following M lines contain two integer numbers each — coordinates of blue points. All coordinates do not exceed 10⁹ by absolute value.

Output:

Output one integer — the number of distinct triangles with vertices in red points which do not contain any blue point inside.

Sample Input:

4 1
0 0
10 0
10 10
5 4
2 1

Sample Output:

2

Sample Input:

5 5
5 10
6 1
8 6
-6 -7
7 -1
5 -1
10 -4
-10 -8
-10 5
-2 -8

Sample Output:

7