#include <cmath>
#include <cstdio>
#include <utility>
#include <algorithm>
using namespace std;
const int N = 1e3;
const double pi = acos(-1);
const double eps = 1e-13;
int n;
struct point {
  long long x, y, dis;
  int id;
  inline point(long long a = 0, long long b = 0, int c = 0) {
    x = a, y = b, id = c;
  }
  inline point operator+(const point &o) const {
    return point(x + o.x, y + o.y);
  }
  inline point operator-(const point &o) const {
    return point(x - o.x, y - o.y);
  }
  inline point operator*(const int &v) const {
    return point(x * v, y * v);
  }
  inline long long operator*(const point &o) const {
    return x * o.y - y * o.x;
  }
  inline bool operator<(const point &o) const {
    return dis < o.dis;
  }
  inline double angle() const {
    return atan2(y, x);
  }
} a[N + 5], t[N + 5];
inline long long dis(const point &a, const point &b) {
  return (a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y);
}
int cnt[N + 5][N + 5][2];
pair<double, int> s[N * N + 5];
int tot;
long long ans;
inline long long calc(const double &L, const double &R) {
  return (upper_bound(s + 1, s + tot + 1, make_pair(R, 0x3f3f3f3f)) - 1)->second - (lower_bound(s + 1,
         s + tot + 1, make_pair(L, -0x3f3f3f3f)) - 1)->second;
}
int main() {
  scanf("%d", &n);
  for (register int i = 1; i <= n; ++i)
    scanf("%lld%lld", &a[i].x, &a[i].y), a[i].id = i, t[i] = a[i];
  for (register int i = 1; i <= n; ++i) {
    for (register int j = 1; j <= n; ++j)
      t[j].dis = dis(t[j], a[i]);
    sort(t + 1, t + n + 1);
    for (register int l = 1, r; l <= n; l = r + 1) {
      for (r = l; r < n && dis(t[r + 1], a[i]) == dis(t[l], a[i]); ++r);
      for (register int j = l; j <= r; ++j)
        for (register int k = j + 1; k <= r; ++k) {
          long long crs = (t[k] - t[j]) * (a[i] - t[j]);
          if (crs)
            ++cnt[t[j].id][t[k].id][crs > 0], ++cnt[t[k].id][t[j].id][crs < 0];
        }
    }
  }
  for (register int i = 1; i <= n; ++i) {
    for (register int j = 1; j <= n; ++j)
      t[j].dis = dis(t[j], a[i]);
    sort(t + 1, t + n + 1), tot = 0;
    for (register int l = 1, r; l <= n; l = r + 1) {
      for (r = l; r < n && dis(t[r + 1], a[i]) == dis(t[l], a[i]); ++r);
      for (register int j = l; j <= r; ++j)
        for (register int k = j + 1; k <= r; ++k) {
          long long crs = (t[k] - t[j]) * (a[i] - t[j]);
          if (crs)
            s[++tot] = make_pair((t[j] + t[k] - a[i] * 2).angle(), cnt[t[j].id][t[k].id][crs < 0]);
        }
    }
    sort(s + 1, s + tot + 1);
    for (register int i = 1; i <= tot; ++i)
      s[i].second += s[i - 1].second;
    for (register int l = 1, r; l <= n; l = r + 1) {
      for (r = l; r < n && dis(t[r + 1], a[i]) == dis(t[l], a[i]); ++r);
      for (register int j = l; j <= r; ++j)
        for (register int k = j + 1; k <= r; ++k) {
          long long crs = (t[k] - t[j]) * (a[i] - t[j]);
          if (crs) {
            int x = j, y = k;
            (t[y] - a[i]) * (t[x] - a[i]) > 0 && (swap(x, y), 1);
            double L = (t[y] - a[i]).angle() + pi / 2, R = (t[x] - a[i]).angle() + pi * 3 / 2;
            L > pi &&(L -= 2 * pi), R > pi && (R -= 2 * pi);
            if (L < R)
              ans += calc(L + eps, R - eps);
            else
              ans += calc(L + eps, pi) + calc(-pi, R - eps);
          }
        }
    }
  }
  ans <<= 2;
  printf("%lld\n", ans);
}