#include <bits/stdc++.h>
using namespace std;
using ll = long long; using pii = pair<ll,ll>;
const ll INF = 1e18;
ll gcd2(ll a, ll b) {
a = labs(a); b = labs(b);
if (a==0) {
return b;
}
if (b==0) {
return a;
}
return gcd(a,b);
}
ll inv(ll x, ll MOD) {
x = (x+MOD*(2-x/MOD))%MOD;
array<ll,3> a = {x,1,0};
array<ll,3> b = {MOD,0,1};
while (b[0]!=1) {
if (a[0]>b[0]) {
swap(a,b);
} else {
ll k = b[0]/a[0];
for (ll i=0;i<3;i++) {
b[i]-=k*a[i];
}
}
}
ll vf = b[1];
vf = (vf+MOD*(2-vf/MOD))%MOD;
return vf;
}
pair<pii,pii> fz(pair<pii,pii> A0, pii pt) {
pii p0 = A0.first; pii p1 = A0.second;
if (A0.second.first==-INF) {
if (p0.first*pt.second!=p0.second*pt.first) {
return {p0,pt};
} else {
return A0;
}
}
ll G = labs(p0.first*p1.second-p0.second*p1.first);
ll G0 = labs(p0.first*pt.second-p0.second*pt.first);
ll G1 = labs(p1.first*pt.second-p1.second*pt.first);
if (G0%G==0 && G1%G==0) {
return A0;
}
//else we can get a better gcd!
ll L1 = p0.first*p1.second-p0.second*p1.first;
ll L2 = p0.first*pt.second-p0.second*pt.first;
ll LG = gcd2(L1,L2);
L1 = L1/LG; L2 = L2/LG;
ll A = inv(L1,L2);
ll B = inv(L2,L1);
pii pfn = {A*p0.first+B*p0.first,A*p0.second+B*p0.second};
return {p0,pfn};
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(0);
ll N; cin >> N;
ll ans = 0;
if (N<=2) {
cout << "-1\n"; exit(0);
}
vector<pii> v0;
pii p0;
ll x1,y1; cin >> x1 >> y1;
p0 = {x1,y1};
ll g1t = 0; ll g2t = 0;
for (ll i=1;i<N;i++) {
ll x2,y2; cin >> x2 >> y2;
v0.push_back({x2-x1,y2-y1});
g1t = gcd2(g1t,x2-x1);
g2t = gcd2(g2t,y2-y1);
}
if (g1t == 0 || g2t == 0) {
cout << "-1\n"; exit(0);
}
pair<pii,pii> mem;
mem = {v0[0],{-INF,-INF}};
for (ll i=1;i<(N-1);i++) {
mem = fz(mem,v0[i]);
}
if (mem.second.first==-INF) {
cout << "-1\n"; exit(0);
} else {
cout << labs(mem.first.first*mem.second.second-mem.first.second*mem.second.first) << "\n";
}
}
