#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const int N=1e5+5;
int n;
struct Point{
ll x,y;
Point norm(){return x<0||(x==0&&y<0)?Point{-x,-y}:*this;}
Point operator+(const Point &p)const{return {x+p.x,y+p.y};}
Point operator-(const Point &p)const{return {x-p.x,y-p.y};}
Point operator*(ll k)const{return {x*k,y*k};}
}p[N];
ll cross(Point a,Point b){return a.x*b.y-a.y*b.x;}
Point gcd(Point a,Point b){
Point c;
c.x=gcd(a.x,b.x);
c.y=gcd(a.y,b.y);
return c.norm();
}
pair<Point,Point> gcd2(Point u,Point v,Point q){
if(cross(u,v)==0)return {gcd(u,v),q};
if(cross(u,q)==0)return {gcd(u,q),v};
if(cross(v,q)==0)return {gcd(v,q),u};
ll d=cross(u,v);
ll a=cross(q,v)/d;
ll b=cross(u,q)/d;
Point r=q-(u*a)-(v*b);
assert(abs(cross(u,r))<abs(cross(u,v)));
return gcd2(u,r,v);
}
int main(){
cin.tie(nullptr)->sync_with_stdio(false);
cin >> n;
for(int i=1;i<=n;i++)cin >> p[i].x >> p[i].y;
for(int i=2;i<=n;i++)p[i]=(p[i]-p[1]).norm();
bool ok=false;
for(int i=3;i<=n;i++)if(cross(p[2],p[i])!=0){
swap(p[3],p[i]);
ok=true;
break;
}
if(!ok)cout << -1,exit(0);
Point u=p[2],v=p[3];
for(int i=4;i<=n;i++)tie(u,v)=gcd2(u,v,p[i]);
cout << abs(cross(u,v));
}
