#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n;
  pair<int, int> A[4];
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> A[i].first >> A[i].second;
  }
  if (n == 1) {
    cout << -1;
    return 0;
  }
  sort(A, A + n);
  if (n == 2) {
    if (A[0].first == A[1].first || A[0].second == A[1].second) {
      cout << -1;
    } else {
      cout << abs(A[0].first - A[1].first) * abs(A[0].second - A[1].second);
    }
  }
  if (n == 3) {
    if (A[0].first == A[1].first) {
      cout << abs(A[0].second - A[1].second) * abs(A[0].first - A[2].first);
    } else {
      cout << abs(A[1].second - A[2].second) * abs(A[2].first - A[0].first);
    }
  }
  if (n == 4) {
    cout << abs(A[0].second - A[1].second) * abs(A[0].first - A[2].first);
  }
  return 0;
}
