#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e5 + 10;
int n;
complex<int> s[MAXN];
int cross(complex<int> a, complex<int> b) { return imag(conj(a) * b); }
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cin >> n;
  int x, y;
  for (int i = 0; i < n; i++) {
    cin >> x >> y;
    s[i] = complex<int>(x, y);
  }
  double tot = -1;
  for (int i = 0; i < n; i++) {
    for (int j = i + 1; j < n; j++) {
      complex<int> a = s[i];
      complex<int> b = s[j];
      double maxi1 = -1;
      for (int k = 0; k < n; k++) {
        complex<int> c = s[k];
        double cc = cross(a - b, c - b);
        if (cc == 0) continue;
        if (cc > 0) maxi1 = max(maxi1, fabs(cc) / 2.0);
      }
      double maxi2 = -1;
      for (int k = 0; k < n; k++) {
        complex<int> c = s[k];
        double cc = cross(a - b, c - b);
        if (cc == 0) continue;
        if (cc < 0) maxi2 = max(maxi2, fabs(cc) / 2.0);
      }
      if (maxi1 != -1 && maxi2 != -1) tot = max(tot, maxi1 + maxi2);
    }
  }
  cout << setprecision(10) << fixed << tot << endl;
  return 0;
}
