#include <bits/stdc++.h>
using namespace std;
long long powm(long long base, long long exp, long long mod = 1000000007) {
  long long ans = 1;
  while (exp) {
    if (exp & 1) ans = (ans * base) % mod;
    exp >>= 1, base = (base * base) % mod;
  }
  return ans;
}
struct Point {
  long long x, y;
} pts[2005];
map<pair<long double, pair<long double, long double>>, long long> m;
inline long double y_intercept(Point p, Point q) {
  if (p.x == q.x) return (long double)1e18;
  return ((long double)(p.y * q.x - p.x * q.y) / (q.x - p.x));
}
inline long double slope(Point p, Point q) {
  if (p.x == q.x) return (long double)1e18;
  return ((long double)(p.y - q.y) / (p.x - q.x));
}
inline long double x_intercept(Point p, Point q) {
  if (p.y == q.y) return (long double)1e18;
  return ((long double)(q.y * p.x - p.y * q.x) / (q.y - p.y));
}
inline long long check(long long x) { return ((1 + sqrt(1 + 8 * x)) / 2); }
inline long long nC3(long long x) { return ((x * (x - 1) * (x - 2)) / 6); }
int main() {
  long long x0, y0, n, x, y, flag = 0, ans = 0;
  scanf("%lld", &n), ans = nC3(n);
  for (long long i = 0; i < n; i++)
    scanf("%lld", &pts[i].x), scanf("%lld", &pts[i].y);
  for (long long i = 0; i < n; i++)
    for (long long j = i + 1; j < n; j++)
      m[{slope(pts[i], pts[j]),
         {x_intercept(pts[i], pts[j]), y_intercept(pts[i], pts[j])}}]++;
  for (auto i : m) ans -= nC3(check(i.second));
  return 0 * printf("%lld ", ans);
}
