#include <bits/stdc++.h>
inline long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
inline void sub(long long &a, long long b) {
  a -= b;
  if (a < 0) a += 1000000007;
}
inline void add(long long &a, long long b) {
  a += b;
  if (a >= 1000000007) a -= 1000000007;
}
template <typename T>
inline T const &MAX(T const &a, T const &b) {
  return a > b ? a : b;
}
template <typename T>
inline T const &MIN(T const &a, T const &b) {
  return a < b ? a : b;
}
inline long long qp(long long a, long long b) {
  long long ans = 1;
  while (b) {
    if (b & 1) ans = ans * a % 1000000007;
    a = a * a % 1000000007, b >>= 1;
  }
  return ans;
}
inline long long qp(long long a, long long b, long long c) {
  long long ans = 1;
  while (b) {
    if (b & 1) ans = ans * a % c;
    a = a * a % c, b >>= 1;
  }
  return ans;
}
using namespace std;
const unsigned long long ba = 233;
const double eps = 1e-5;
const long long INF = 0x3f3f3f3f3f3f3f3f;
const int N = 1000 + 10, maxn = 1000000 + 10, inf = 0x3f3f3f3f;
pair<int, int> p[N];
map<pair<int, int>, int> t;
set<pair<int, int> > s[N];
int main() {
  int n;
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) scanf("%d%d", &p[i].first, &p[i].second);
  int cnt = 0;
  for (int i = 1; i <= n; i++)
    for (int j = 1; j < i; j++) {
      int x = p[i].first - p[j].first, y = p[i].second - p[j].second,
          z = gcd(x, y);
      x /= z, y /= z;
      if (x < 0) x = -x, y = -y;
      if (s[i].find(make_pair(x, y)) == s[i].end() &&
          s[j].find(make_pair(x, y)) == s[j].end())
        t[make_pair(x, y)]++, cnt++;
      s[i].insert(make_pair(x, y));
      s[j].insert(make_pair(x, y));
    }
  long long ans = 1ll * cnt * (cnt - 1) / 2;
  for (auto q : t) ans -= q.second * (q.second - 1) / 2;
  printf("%lld\n", ans);
  return 0;
}
