#include <bits/stdc++.h>
#define sz(s) (int)s.size()
using namespace std;
const int MAXN = 1e5+5;
typedef long long ll;
typedef array<ll, 2> pt;
ll operator*(pt a, pt b) {
return a[0]*b[1] - a[1]*b[0];
}
ll dot(pt a, pt b) {
return a[0]*b[0] + a[1]*b[1];
}
pt operator*(ll a, pt b) {
return {a*b[0], a*b[1]};
}
pt operator/(pt a, ll b) {
return {a[0]/b,a[1]/b};
}
pt operator+(pt a, pt b) {
return {a[0]+b[0], a[1]+b[1]};
}
pt operator-(pt a, pt b) {
return {a[0]-b[0], a[1]-b[1]};
}
ll _abs(ll a) {
return a < 0 ? -a : a;
}
ll l1(pt a) {
return _abs(a[0]) + _abs(a[1]);
}
ll _gcd(ll a, ll b) {
a = _abs(a);
b = _abs(b);
assert(a+b);
int shift = 0;
while (a && b) {
if (!(a&1) && !(b&1)) {
shift++;
a >>= 1; b >>= 1;
continue;
}
if (!(a&1)) {
a >>= 1;
continue;
}
if (!(b&1)) {
b >>= 1;
continue;
}
if (a > b) a = (a-b)/2;
else b = (b-a)/2;
}
return (a+b) << shift;
}
struct cmp {
bool operator()(pt a, pt b) {
int d = l1(a)-l1(b);
return d == 0 ? (a < b) : (d < 0);
}
} cmp;
ll round_to(ll a, ll b) {
if (a < 0) return -round_to(-a, b);
return a / b + ((a % b)*2 >= b);
}
pt proj(pt c, pt a, pt b) {
ll dem = a*b;
ll num1 = c*b;
ll num2 = a*c;
if (dem < 0) {
num1 *= -1;
num2 *= -1;
dem *= -1;
}
num1 = round_to(num1, dem);
num2 = round_to(num2, dem);
return c - (num1*a + num2*b);
}
pt reduce_two(pt a, pt b) {
assert(a*b == 0);
ll g = _gcd(l1(a), l1(b));
ll m = l1(a)/g;
return a / m;
}
void reduce(vector<pt> &basis) {
if (sz(basis) == 1) return;
else if (sz(basis) == 2) {
if (basis[0]*basis[1] == 0) {
basis[0] = reduce_two(basis[0], basis[1]);
basis.pop_back();
// ll g = _gcd(l1(basis[0]), l1(basis[1]));
// ll m = l1(basis[0])/g;
// basis[0][0] /= m;
// basis[0][1] /= m;
// basis.pop_back();
}
else return;
}
else {
assert(sz(basis) == 3);
sort(basis.begin(), basis.end(), cmp);
for (int i = 2; i >= 0; i--) {
pt a = basis[i == 0];
pt b = basis[1 + (i <= 1)];
if (a*b == 0) {
pt n1 = reduce_two(a, b);
pt c = basis[i];
basis[0] = n1;
basis[1] = c;
basis.pop_back();
return reduce(basis);
}
pt c = basis[i];
pt res = proj(c, a, b);
if (l1(res) < l1(c)) {
if (l1(res) == 0) {
basis[0] = a;
basis[1] = b;
basis.pop_back();
}
else basis[i] = res;
return reduce(basis);
}
}
assert(false);
}
}
void read(pt &p) {
cin >> p[0] >> p[1];
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(NULL);
int n; cin >> n;
pt p; read(p);
n--;
vector<pt> basis;
for (int i = 0; i < n; i++) {
pt v; read(v);
basis.push_back(v-p);
reduce(basis);
p = v;
}
if (sz(basis) <= 1) cout << "-1\n";
else cout << _abs(basis[0]*basis[1]) << '\n';
}
