#include <bits/stdc++.h>
int a[5], b[5];
int main() {
  int n, i, r = 0, z, x1, y1, x2, y2;
  scanf("%d", &n);
  for (i = 0; i < n; i++) scanf("%d %d", &a[i], &b[i]);
  if (n == 1)
    printf("-1");
  else {
    for (i = 1; i < n; i++)
      for (int j = 0; j < i; j++) {
        z = (a[i] - a[j]) * (b[i] - b[j]);
        if (z < 0) z = -z;
        if (r < z) r = z;
      }
    if (r == 0) r = -1;
    printf("%d", r);
  }
  return 0;
}
