#include <bits/stdc++.h>
#define ll long long
#define pll pair<ll,ll>
#define F first
#define S second
using namespace std;
pll fd(pll x){
return max(x,{-x.F,-x.S});
}
pll base(pll x){
if(x.F==0)return {0,1};
else if(x.S==0)return {1,0};
else {
ll g=gcd(abs(x.F),abs(x.S));
return {x.F/g,x.S/g};
}
}
pll gg(pll x,pll y){
if(x.F==0){
return {0,gcd(abs(x.S),abs(y.S))};
}else if(x.S==0){
return {gcd(abs(x.F),abs(y.F)),0};
}else{
ll gf=gcd(abs(x.F),abs(y.F)),gs=gcd(abs(x.S),abs(y.S));
return fd({gf,gs});
}
}
bool build(pll x,pll y,pll tar){
ll X=abs(y.F*tar.S-y.S*tar.F),Y=abs(x.F*tar.S-x.S*tar.F),D=abs(y.F*x.S-y.S*x.F);
if(X%D==0&&Y%D==0)return 1;
return 0;
}
int n;
vector<pll> point;
vector<pll> vc;
vector<pll> use;
int main(){
// ios::sync_with_stdio(0);
// cin.tie(0);
cin>>n;
for(int i=0;i<n;i++){
ll x,y;
cin>>x>>y;
point.push_back({x,y});
}
for(int i=1;i<n;i++){
vc.push_back(fd({point[i].F-point[0].F,point[i].S-point[0].S}));
}
for(auto x:vc){
assert(x.F>=0);
int ok=1;
for(auto y:use){
if(base(x)==base(y)){
y=gg(x,y);
ok=0;
break;
}
}
if(ok==1){
if(use.size()<2)use.push_back(x);
else{
if(build(use[0],x,use[1])){
use[1]=x;
}else if(build(use[1],x,use[0])){
use[0]=x;
}
}
}
if(use.size()>=3){
break;
}
}
if(use.size()>=3){
cout<<"1\n";
}else if(use.size()<=1){
cout<<"-1\n";
}else{
sort(use.begin(),use.end());
if(use[0].F==0){
cout<<abs(use[0].S*use[1].F)<<"\n";
}else{
ll g=gcd(abs(use[0].F),abs(use[1].F));
ll diff=abs(use[0].S*use[1].F/g-use[1].S*use[0].F/g);
cout<<g*diff<<"\n";
}
}
return 0;
}
