Quadrilaterals

You are given N points in general position on a plane, meaning no two points are the same and no three points lie on a single straight line. Your task is to determine how many distinct convex quadrilaterals can be formed using these points as vertices.

Input

The first line of the input contains a single integer N (4 ≤ N ≤ 1500). Each of the following N lines contains two integers X_i and Y_i, representing the coordinates of a point. The absolute value of each coordinate does not exceed 10^8.

Output

Output a single integer representing the number of distinct convex quadrilaterals that can be formed with the given points as vertices.

Examples