#include <bits/stdc++.h>
using namespace std;
long long n;
class point {
 public:
  long long x;
  long long y;
  point(long long _x, long long _y) { x = _x, y = _y; }
  point() { point(0, 0); }
};
point p[2015];
map<pair<long long, pair<long long, long long> >, long long> lines;
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
int main() {
  cin >> n;
  long long ans = 1LL * n * (n - 1) * (n - 2) / 6;
  for (long long i = 0; i < n; ++i) cin >> p[i].x >> p[i].y;
  for (long long i = 0; i < n; ++i) {
    lines.clear();
    for (long long j = i + 1; j < n; ++j) {
      long long a = p[i].y - p[j].y, b = p[j].x - p[i].x,
                c = -a * p[j].x - b * p[j].y;
      if (a < 0 || (a == 0 && b < 0)) {
        a = -a, b = -b, c = -c;
      }
      long long g = gcd(abs(a), abs(b));
      g = gcd(g, abs(c));
      c /= g, b /= g, a /= g;
      lines[make_pair(a, make_pair(b, c))]++;
    }
    for (map<pair<long long, pair<long long, long long> >, long long>::iterator
             it = lines.begin();
         it != lines.end(); ++it) {
      ans -= it->second * (it->second - 1LL) / 2LL;
    }
  }
  cout << ans << endl;
  return 0;
}
