Vanya and Triangles

Description:

Input:

The first line contains integer n (1 ≤ n ≤ 2000) — the number of the points painted on the plane.

Next n lines contain two integers each x_i, y_i ( - 100 ≤ x_i, y_i ≤ 100) — the coordinates of the i-th point. It is guaranteed that no two given points coincide.

Output:

In the first line print an integer — the number of triangles with the non-zero area among the painted points.

Sample Input:

4
0 0
1 1
2 0
2 2

Sample Output:

3

Sample Input:

3
0 0
1 1
2 0

Sample Output:

1

Sample Input:

1
1 1

Sample Output:

0

Note:

Note to the first sample test. There are 3 triangles formed: (0, 0) - (1, 1) - (2, 0); (0, 0) - (2, 2) - (2, 0); (1, 1) - (2, 2) - (2, 0).

Note to the second sample test. There is 1 triangle formed: (0, 0) - (1, 1) - (2, 0).

Note to the third sample test. A single point doesn't form a single triangle.