#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int n, x, y;
map<int, vector<ll>> mpx, mpy;
vector<ll> xs, ys;
int main() {
cin.tie(0) -> sync_with_stdio(0);
cin >> n;
for(int i=0;i<n;i++) {
cin >> x >> y;
xs.push_back(x); ys.push_back(y);
mpx[x].push_back(y);
mpy[y].push_back(x);
}
sort(xs.begin(), xs.end()); sort(ys.begin(), ys.end());
for(auto &e:mpx) sort(e.second.begin(), e.second.end());
for(auto &e:mpy) sort(e.second.begin(), e.second.end());
ll ans = -1;
ll cgcd = 0;
for(auto &e:mpx) {
for(int i=1;i<e.second.size();i++) {
cgcd = __gcd(cgcd, e.second[i] - e.second[i-1]);
}
}
if(cgcd) {
ll cgcd2 = 0;
for(int i=1;i<xs.size();i++) cgcd2 = __gcd(cgcd2, xs[i] - xs[i-1]);
ans = max(ans, cgcd*cgcd2);
}
if(!ans) ans = -1;
cgcd = 0;
for(auto &e:mpy) {
for(int i=1;i<e.second.size();i++) {
cgcd = __gcd(cgcd, e.second[i] - e.second[i-1]);
}
}
if(cgcd) {
ll cgcd2 = 0;
for(int i=1;i<ys.size();i++) cgcd2 = __gcd(cgcd2, ys[i] - ys[i-1]);
ans = max(ans, cgcd*cgcd2);
}
if(!ans) ans = -1;
cout << ans;
}
