#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
const int mod2 = 998244353;
void fact_init(int n);
long long exp(long long taban, long long us, long long md);
long long ebob(long long a, long long b);
long long ekok(long long a, long long b);
long long komb(long long a, long long b);
vector<long long> fact;
vector<long long> inv_fact;
void fact_init(int n) {
  fact.resize(n + 5);
  inv_fact.resize(n + 5);
  fact[0] = inv_fact[0] = 1;
  for (int i = 1; i <= n; i++) {
    fact[i] = (fact[i - 1] * i) % mod;
    inv_fact[i] = exp(fact[i], mod - 2, mod);
  }
}
long long exp(long long taban, long long us, long long md) {
  long long carpan = taban % md;
  if (carpan == 0) return 0;
  long long temp = us;
  long long res = 1;
  while (temp) {
    if (temp % 2) res = (res * carpan) % md;
    temp /= 2;
    carpan = (carpan * carpan) % md;
  }
  return res;
}
long long ebob(long long a, long long b) {
  if (!a) return b;
  return ebob(b % a, a);
}
long long ekok(long long a, long long b) { return (a * b) / ebob(a, b); }
long long komb(long long a, long long b) {
  if (a < b) return 0;
  return fact[a] * (inv_fact[a - b] * inv_fact[b] % mod) % mod;
}
const int N = 1e5 + 5;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(NULL);
  int n;
  cin >> n;
  vector<pair<int, int> > points;
  long long ans = (long long)n * (n - 1) * (n - 2) / 6;
  for (int i = 0; i < n; i++) {
    int x, y;
    cin >> x >> y;
    unordered_map<double, int> cnt;
    int cnt_vert = 0;
    for (auto p : points) {
      int dx = x - p.first, dy = y - p.second;
      if (dx == 0)
        cnt_vert++;
      else {
        cnt[(double)dy / dx]++;
      }
    }
    long long cikar = cnt_vert * (cnt_vert - 1) / 2;
    for (auto c : cnt) {
      int cc = c.second;
      cikar += cc * (cc - 1) / 2;
    }
    ans -= cikar;
    points.push_back(make_pair(x, y));
  }
  cout << ans << "\n";
}
