#include <bits/stdc++.h>
using namespace std;
#define int long long

struct Point{
    int x, y;
};

const int N = 1001;
vector<Point>v(N);
vector<pair<int, int>>p;
vector<int>parent(2*N), s(2*N, 1);

int fordul(Point a, Point b, Point c)
{
    int w = (b.x - a.x) * (c.y - a.y) - (b.y - a.y) * (c.x - a.x);
    if(w < 0) return -1;
    if(w > 0) return 1;
    return 0;
}

bool metsz(Point a, Point b, Point c, Point d)
{
    return (fordul(a, b, c) * fordul(a, b, d) == -1 && fordul(c, d, a) * fordul(c, d, b) == -1);
}

int dist(Point a, Point b)
{
    return (a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y);
}

bool srt(pair<int, int>a, pair<int, int>b)
{
    pair<Point, Point> x = {v[a.first], v[a.second]}, y = {v[b.first], v[b.second]};
    return dist(x.first, x.second) < dist(y.first, y.second);
}

int holvan(int a)
{
    if(a == parent[a]) return a;
    parent[a] = holvan(parent[a]);
    return parent[a];
}

bool unio(int a, int b)
{
    int x = holvan(a), y = holvan(b);
    if(x != y)
    {
        if(s[x] < s[y]) swap(x, y);
        s[x] += s[y];
        parent[y] = x;
        return 0;
    }
    return 1;
}

signed main() {
    ios::sync_with_stdio(false);cin.tie(nullptr);
	int n; cin >> n;
    for(int i = 1; i <= n; i++)
    {
        cin >> v[i].x >> v[i].y;
    }
    for(int i = 1; i <= n; i++)
        for(int j = i+1; j <= n; j++)
            p.push_back({i, j});
    sort(p.begin(), p.end(), srt);
    for(int i = 1; i <= 2*n; i++) parent[i] = i;
    Point origo = {0LL, 0LL};
    Point k = {1000000001LL, 1LL};
    for(int i = 0; i < p.size(); i++)
    {
        bool x = metsz(origo, k, v[p[i].first], v[p[i].second]);
        int p1 = p[i].first, p2 = p[i].second, p3 = p1+n, p4 = p2+n;
        if(x) swap(p2, p4);
        if(unio(p1, p2) || unio(p3, p4))
        {
            bool ans = (holvan(p1) == holvan(p1+n));
            if(ans) {cout << dist(v[p[i].first], v[p[i].second]); return 0;}
        }
    }
    cout << -1;
}