#include <bits/stdc++.h>
using namespace std;
bool area(int x1, int y1, int x2, int y2, int x3, int y3) {
  int x, y, z;
  x = x1 * (y2 - y3);
  y = x2 * (y3 - y1);
  z = x3 * (y1 - y2);
  float res;
  if (x + y + z == 0)
    return false;
  else
    return true;
}
int main() {
  long long w, m, i, ans = 0, a[2005], b[2005], j, k;
  cin >> m;
  for (i = 0; i < m; i++) cin >> a[i] >> b[i];
  for (i = 0; i < m; i++) {
    for (j = i + 1; j < m; j++) {
      for (k = j + 1; k < m; k++) {
        w = area(a[i], b[i], a[j], b[j], a[k], b[k]);
        if (w == 1) ans++;
      }
    }
  }
  cout << ans;
  return 0;
}
