#include <stdio.h>
#include <algorithm>
#include <vector>
using namespace std;

constexpr double kEps = 1E-10;
constexpr int kN = int(4E3 + 10), kInf = int(1E9 + 10);
#define PB push_back

struct Point {
	double x, y;
	Point(double a, double b) {x = a, y = b;}
	Point() {}
	void in() {
		scanf("%lf%lf", &x, &y);
		return ;
	}
	inline Point operator -(Point b) const {return Point(x - b.x, y - b.y);}
	inline Point operator /(double b) const {return Point(x / b, y / b);}
	inline double operator *(Point b) const {return x * b.x + y * b.y;}
	inline double operator ^(Point b) const {return x * b.y - y * b.x;}
};

struct Line {
	double a, b, c;
	Line(Point pa, Point pb) :a(pa.y - pb.y), b(pb.x - pa.x), c(pa ^ pb){}
};


const Point O(0, 0);

int dcmp(double x) {return x > kEps ? 1 : x < -kEps ? -1 : 0;}

inline Point line_intersection(Line l1, Line l2) {
	return Point(-l1.b * l2.c + l1.c * l2.b, l1.a * l2.c - l1.c * l2.a) / (-l1.a * l2.b + l1.b * l2.a);
}

inline bool onsegment(Point p, Point a, Point b) {
	return dcmp((a - p) * (b - p)) < -kEps;
}

int n;
Point p[kN];
bool cmp(int a, int b) {return (p[a] ^ p[b]) > kEps;}

int cnt(int x) {
	vector<int> left, right;
	int lpos = 0, rpos = 0, lsz, rsz, ans = 0;
	Line l(p[x], O);
	double tmp;
	for (int i = 1; i <= n; i++) if (i != x) {
		tmp = p[i] ^ p[x];
		if (tmp < -kEps) left.PB(i);
		else if (tmp > kEps) right.PB(i);
	}	

	sort(left.begin(), left.end(), cmp);
	sort(right.begin(), right.end(), cmp);
	
	lsz = int(left.size());
	rsz = int(right.size());
	
	while (lpos < lsz) {
		while (rpos < rsz) {
			if (onsegment(O, line_intersection(l, Line(p[left[lpos]], p[right[rpos]])), p[x])) rpos++;
			else break;
		}
		ans += rpos;
		lpos++;
	}
	
	return ans;
}

int main() {
	long long int ans = 0;
	scanf("%d", &n);
	for (int i = 1; i <= n; i++) p[i].in();

	for (int i = 1; i <= n; i++) ans += cnt(i);	
	printf("%lld\n", ans / 3);
}