#include <bits/stdc++.h>
typedef struct pts_s {
  short x;
  short y;
} pts_t;
pts_t pts[2048];
static void do_tri(int n) {
  int i, j, k;
  int ans = 0;
  for (i = 0; i < n; i++) {
    for (j = i + 1; j < n; j++) {
      int dy1 = pts[i].y - pts[j].y;
      int dx1 = pts[i].x - pts[j].x;
      for (k = j + 1; k < n; k++) {
        int dy2 = pts[i].y - pts[k].y;
        int dx2 = pts[i].x - pts[k].x;
        if (dy1 * dx2 != dy2 * dx1) {
          ++ans;
        }
      }
    }
  }
  printf("%d\n", ans);
  return;
}
int main() {
  int n;
  int i;
  scanf("%d", &n);
  for (i = 0; i < n; i++) {
    scanf("%hd%hd", &pts[i].x, &pts[i].y);
  }
  do_tri(n);
  return 0;
}
