#include <bits/stdc++.h>
using namespace std;
int x[2010], y[2010];
int qnt[2010];
vector<double> m[2010];
const double eps = 1e-9;
int main() {
  memset((qnt), (0), (sizeof(qnt)));
  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; ++i) scanf("%d%d", &x[i], &y[i]);
  for (int i = 0; i < n; ++i) {
    qnt[x[i] + 200]++;
    m[i].clear();
    for (int j = 0; j < n; ++j)
      if (i != j) {
        if (x[i] != x[j]) {
          int a = i, b = j;
          m[i].push_back(double((y[b] - y[a])) / (x[b] - x[a]));
        }
      }
  }
  for (int i = 0; i < n; ++i) sort(m[i].begin(), m[i].end());
  long long ans = 0;
  for (int i = 0; i < n; ++i) {
    long long tmp = 0;
    for (int j = 0; j < n; ++j)
      if (i != j) {
        int a = i, b = j;
        int r;
        if (x[a] == x[b])
          r = qnt[x[a] + 200] - 2;
        else {
          double ang = double(y[b] - y[a]) / (x[b] - x[a]);
          r = upper_bound(m[i].begin(), m[i].end(), ang + eps) -
              lower_bound(m[i].begin(), m[i].end(), ang - eps) - 1;
        }
        tmp += n - 2 - r;
      }
    ans += tmp;
  }
  cout << ans / 6 << endl;
}
