#include <bits/stdc++.h>
int n, i, j, k, x[2001] = {}, y[2001] = {}, z;
long long sum = 0;
int main() {
  scanf("%d", &n);
  for (i = 1; i <= n; i++) scanf("%d %d", &x[i], &y[i]);
  for (i = 1; i <= n - 2; i++) {
    for (j = i + 1; j <= n - 1; j++) {
      for (k = j + 1; k <= n; k++) {
        z = x[i] * y[j] + x[j] * y[k] + x[k] * y[i] - x[j] * y[i] -
            x[k] * y[j] - y[k] * x[i];
        if (z != 0) sum++;
      }
    }
  }
  printf("%I64u\n", sum);
}
