#include <bits/stdc++.h>
using namespace std;
void scan(int &x) {
  register int c = getchar();
  x = 0;
  int neg = 0;
  for (; ((c < 48 || c > 57) && c != '-'); c = getchar())
    ;
  if (c == '-') {
    neg = 1;
    c = getchar();
  }
  for (; c > 47 && c < 58; c = getchar()) {
    x = (x << 1) + (x << 3) + c - 48;
  }
  if (neg) x = -x;
}
const int M = 2005;
map<double, int> mm[M];
int n, x[M], y[M], cnt[M];
int main() {
  scanf("%d", &n);
  for (int i = 0; i < n; i++) scanf("%d%d", &x[i], &y[i]);
  int ct = 0;
  for (int i = 0; i < n; i++) {
    for (int j = i + 1; j < n; j++) {
      double m1 = x[i] == x[j] ? 2000000000
                               : (double)(y[i] - y[j]) / (double)(x[i] - x[j]);
      mm[i][m1]++;
      cnt[i]++;
    }
  }
  for (int i = 0; i < n; i++) {
    for (int j = i + 1; j < n; j++) {
      double m1 = x[i] == x[j] ? 2000000000
                               : (double)(y[i] - y[j]) / (double)(x[i] - x[j]);
      ct += cnt[j] - mm[j][m1];
    }
  }
  printf("%d\n", ct);
  return 0;
}
