// Source: https://usaco.guide/general/io

#include <bits/stdc++.h>
using namespace std;
using ll=long long;
struct pont{
    ll x,y;
};
vector<pont> v;

int fordul(pont a,pont b){
  ll s=a.x*b.y-a.y*b.x;
  return (s>0)-(s<0); 
}

int val(pont a,pont b){
    if (a.y>b.y) swap(a,b);
    if (a.y<0 && b.y>=0 && fordul(a,b)==1) return 1;
    return 0;
}

ll dist(int a, int b){
    ll x = v[a].x-v[b].x;
    ll y = v[a].y-v[b].y;
    return x*x+y*y;
}



struct edge{
    ll a,b;

    ll len() const {
        ll x = v[a].x-v[b].x;
        ll y = v[a].y-v[b].y;
        return x*x+y*y;
    }

    auto operator< (const edge &other) {
        return len()<other.len();
    }
};
vector<edge> e;

vector<int> c;
int n;
bool dfs(int cs, ll d){
    for (int to=0;to<n;to++){
        if (to==cs) continue;
        if (dist(cs,to)>d) continue;
        if (c[to]!=-1){
            if ((val(v[cs], v[to])+c[cs]+c[to])%2) return false;
            continue;
        }
        if (val(v[cs], v[to])) c[to]=1-c[cs];
        else c[to]=c[cs];
        if (!dfs(to,d)) return false;
    }
    return true;
}

int main() {
    cin>>n;
    v.resize(n);
    c.resize(n,-1);
    for (auto &i : v) cin>>i.x>>i.y;
    for (int i=0;i<n;i++){
        for (int j=i+1;j<n;j++){
            e.push_back({i,j});
        }
    }
    sort(e.begin(), e.end());
    ll l=-1,r=e.size();
    while (l+1<r){
        ll mid=(l+r)/2;
        c.assign(n,-1);
        bool kor=true;
        for (int i=0;i<n;i++) if(c[i]==-1) {
            c[i]=0;
            kor = min(dfs(i, e[mid].len()),kor);
        }
        if (!kor){
            r=mid;
        }
        else {
            l=mid;
        }
    }


    if (r==e.size()){
        cout<<-1;
        return 0;
    }
    cout<<e[r].len();
}