#include <bits/stdc++.h>
using namespace std;
int max1(int x, int y, int z = 0) {
  int a = abs(x);
  int b = abs(y);
  int c = abs(z);
  if (a > b && a > c) {
    return a;
  } else if (b > a && b > c) {
    return b;
  } else {
    return c;
  }
}
int main() {
  int k, i;
  int a[4][2];
  cin >> k;
  for (i = 0; i < k; i++) {
    cin >> a[i][0] >> a[i][1];
  }
  if (k == 1) {
    cout << "-1";
  }
  if (k == 2) {
    int res = abs((a[0][0] - a[1][0]) * (a[0][1] - a[1][1]));
    if (res == 0) {
      cout << "-1";
    } else {
      cout << res;
    }
  }
  if (k == 3) {
    int res = max1((a[0][0] - a[1][0]) * (a[0][1] - a[1][1]),
                   (a[0][0] - a[2][0]) * (a[0][1] - a[2][1]),
                   (a[1][0] - a[2][0]) * (a[1][1] - a[2][1]));
    cout << res;
  }
  if (k == 4) {
    int res = max1((a[0][0] - a[1][0]) * (a[0][1] - a[1][1]),
                   (a[0][0] - a[2][0]) * (a[0][1] - a[2][1]),
                   (a[0][0] - a[3][0]) * (a[0][1] - a[3][1]));
    cout << res;
  }
}
