#include <bits/stdc++.h>
using namespace std;
struct line {
  int a, b, c;
  bool operator<(const line& other) const {
    return (a < other.a || (a == other.a && b < other.b) ||
            (a == other.a && b == other.b && c < other.c));
  }
  line(int A, int B, int C) { a = A, b = B, c = C; }
};
int n;
int x[2001], y[2001];
map<line, long long> m;
int gcd(int a, int b) {
  while (a && b) a > b ? a %= b : b %= a;
  return (a + b);
}
int main() {
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> x[i] >> y[i];
  }
  if (n < 3) {
    cout << 0;
    return 0;
  }
  for (int i = 0; i < n; i++)
    for (int j = i + 1; j < n; j++) {
      int px = x[i], py = y[i];
      int qx = x[j], qy = y[j];
      int a = py - qy;
      int b = qx - px;
      int c = -a * px - b * py;
      int g = gcd(abs(a), gcd(abs(b), abs(c)));
      a /= g, b /= g, c /= g;
      if (a < 0) {
        a *= -1, b *= -1, c *= -1;
      } else if (a == 0) {
        if (b < 0) b *= -1, c *= -1;
      }
      m[line(a, b, c)]++;
    }
  long long h = n + 0ll;
  long long res = h * (h - 1) * (h - 2) / 6;
  for (map<line, long long>::iterator it = m.begin(); it != m.end(); it++) {
    long long current = it->second;
    current *= 2ll;
    if (current >= 2) {
      long long o = (long long)(sqrt(current + 0.0f));
      for (long long l = o - 1; l <= o + 1; l++)
        if (l * (l - 1) == current) {
          current = l;
          break;
        }
    }
    if (current >= 3) {
      res -= current * (current - 1) * (current - 2) / 6;
    }
  }
  cout << res;
  return 0;
}
