#include <bits/stdc++.h>
using namespace std;
const long long INF = 1000000000000000000ll;
long long x[6], y[6];
int main() {
  ios_base::sync_with_stdio(0);
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) cin >> x[i] >> y[i];
  if (n == 1) {
    cout << -1 << endl;
    return 0;
  }
  if (n == 2) {
    if (x[0] == x[1] || y[0] == y[1]) {
      cout << -1 << endl;
      return 0;
    }
    long long s = (abs(x[0] - x[1]) * abs(y[0] - y[1]));
    cout << s << endl;
    return 0;
  }
  long long X = 0, Y = 0;
  for (int i = 1; i < n; i++) {
    X = max(X, abs(x[0] - x[i]));
    Y = max(Y, abs(y[0] - y[i]));
  }
  cout << X * Y << endl;
}
