#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, x[5], y[5], i;
  cin >> n;
  for (i = 1; i <= n; i++) cin >> x[i] >> y[i];
  if (n == 1)
    cout << -1;
  else if (n == 2) {
    if (x[1] != x[2] && y[1] != y[2])
      cout << abs(x[1] - x[2]) * abs(y[1] - y[2]);
    else
      cout << -1;
  } else if (n == 3) {
    if (x[1] == x[2] && y[1] == y[3])
      cout << abs(y[2] - y[1]) * abs(x[3] - x[1]);
    else if (x[1] == x[2] && y[2] == y[3])
      cout << abs(y[2] - y[1]) * abs(x[3] - x[2]);
    else if (x[2] == x[3] && y[2] == y[1])
      cout << abs(y[2] - y[3]) * abs(x[2] - x[1]);
    else if (x[2] == x[3] && y[3] == y[1])
      cout << abs(y[2] - y[3]) * abs(x[3] - x[1]);
    else if (x[1] == x[3] && y[2] == y[1])
      cout << abs(y[1] - y[3]) * abs(x[2] - x[1]);
    else if (x[1] == x[3] && y[3] == y[2])
      cout << abs(y[1] - y[3]) * abs(x[3] - x[2]);
  } else if (n == 4) {
    int x1 = 10000, x2 = -10000, y1 = 10000, y2 = -10000;
    for (i = 1; i <= 4; i++) {
      if (x[i] < x1) x1 = x[i];
      if (x[i] > x2) x2 = x[i];
      if (y[i] < y1) y1 = y[i];
      if (y[i] > y2) y2 = y[i];
    }
    cout << (x2 - x1) * (y2 - y1);
  }
}
