#include <bits/stdc++.h>
#define pb push_back
#define pf push_front
using namespace std;
#define F first
#define S second
typedef long long ll;
#define pii pair <int, int>
#define pll pair <ll, ll>
typedef long double ld;
const ll N = 1e5 + 100, M = 4096 + 10, len = 315, inf = 1e18;
const ll mod = 1e9 + 7;
ll um(ll a, ll b){
	return (1LL * a * b) % mod;
}
ll subr(ll a, ll b){
	return ((1LL * a - b) % mod + mod) % mod;
}
pll a[N];
ll calc(ll x, ll b, ll c){
	return abs(a[x].S - a[b].S) * abs(a[c].F - a[x].F);
}
ll cc(ll x, ll b, ll c){
	return abs(a[x].F - a[b].F) * abs(a[c].S - a[x].S);
}
int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	cout.tie(nullptr);
	ll n;
	cin >> n;
	for(ll i = 0; i < n; i++){
		cin >> a[i].F >> a[i].S;
	}
	if(n <= 2){
		cout << -1;
		return 0;
	}
	if(n == 3){
		if(a[0].F == a[1].F && a[1].F == a[2].F){
			cout << -1;
			return 0;
		}
		if(a[0].S == a[1].S && a[1].S == a[2].S){
			cout << -1;
			return 0;
		}
		if(a[0].F == a[1].F){
			cout << calc(0, 1, 2);
			return 0;
		}
		if(a[0].F == a[2].F){
			cout << calc(0, 2, 1);
			return 0;
		}
		if(a[1].F == a[2].F){
			cout << calc(1, 2, 0);
			return 0;
		}
		
		if(a[0].S == a[1].S){
			cout << calc(0, 1, 2);
			return 0;
		}
		if(a[0].S == a[2].S){
			cout << cc(0, 2, 1);
			return 0;
		}
		if(a[1].S == a[2].S){
			cout << cc(1, 2, 0);
			return 0;
		}
		return -1;
	}
  return 0;
}