#include <bits/stdc++.h>
using namespace std;
struct Point {
  double x, y;
  Point(double x = 0, double y = 1) : x(x), y(y) {}
};
Point operator+(Point A, Point B) { return Point(A.x + B.x, A.y + B.y); }
Point operator-(Point A, Point B) { return Point(A.x - B.x, A.y - B.y); }
Point operator*(Point A, double p) { return Point(A.x * p, A.y * p); }
Point operator/(Point A, double p) { return Point(A.x / p, A.y / p); }
bool operator<(const Point& a, const Point& b) {
  return a.x < b.x || (a.x == b.x && a.y < b.y);
}
const double eps = 1e-10;
int dcmp(double x) {
  if (fabs(x) < eps)
    return 0;
  else
    return x < 0 ? -1 : 1;
}
bool operator==(const Point& a, const Point& b) {
  return dcmp(a.x - b.x) == 0 && dcmp(a.y - b.y) == 0;
}
double Dot(Point A, Point B) { return A.x * B.x + A.y * B.y; }
double length(Point A) { return sqrt(Dot(A, A)); }
double Angle(Point A, Point B) {
  return acos(Dot(A, B) / length(A) / length(B));
}
double Cross(Point A, Point B) { return A.x * B.y - B.x * A.y; }
double Area2(Point A, Point B, Point C) { return Cross(B - A, C - A); }
inline Point read_point(Point& P) {
  scanf("%lf%lf", &P.x, &P.y);
  return P;
}
int main() {
  int n;
  Point po[2005];
  scanf("%d", &n);
  for (int i = 0; i < n; i++) read_point(po[i]);
  if (n < 3) {
    printf("0\n");
    return 0;
  }
  int cnt = 0;
  for (int i = 0; i < n; i++) {
    for (int j = i + 1; j < n; j++) {
      for (int k = j + 1; k < n; k++) {
        if (Area2(po[i], po[j], po[k]) != 0) cnt++;
      }
    }
  }
  printf("%d\n", cnt);
  return 0;
}
