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

typedef long long int ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<pair<int, int> > vii;
#define rrep(i, m, n) for(int (i)=(m); (i)<(n);  (i)++)
#define erep(i, m, n) for(int (i)=(m); (i)<=(n); (i)++)
#define  rep(i, n)    for(int (i)=0; (i)<(n);  (i)++)
#define rrev(i, m, n) for(int (i)=(n)-1; (i)>=(m); (i)--)
#define erev(i, m, n) for(int (i)=(n); (i)>=(m); (i)--)
#define  rev(i, n)    for(int (i)=(n)-1; (i)>=0; (i)--)
#define vrep(i, c)    for(__typeof((c).begin())i=(c).begin(); i!=(c).end(); i++)
#define  ALL(v)       (v).begin(), (v).end()
#define pb            push_back
#define mp            make_pair
template<class T, class S> inline bool minup(T& m, const S x){ return m>(T)x ? (m=(T)x, true) : false; }
template<class T, class S> inline bool maxup(T& m, const S x){ return m<(T)x ? (m=(T)x, true) : false; }

static const int    INF = 1000000000;
static const ll     MOD = 1000000007LL;
static const double EPS = 1E-10;

template<typename S, typename T> T add(S x, T y){ if(abs(x+y) < EPS*(abs(x)+abs(y))) return 0; return x + y; }
template<typename T> inline bool semieq(T x, T y){ return abs(x - y) < EPS; }
template<typename T> inline bool semige(T x, T y){ return y - x < -EPS; }
template<typename T> inline bool semile(T x, T y){ return x - y < -EPS; }


struct Point : public complex<double>
{
public:
  Point(const double x = 0.0, const double y = 0.0) { this->real(x);  this->imag(y); }
  Point(const complex<double> w)  { this->real(w.real());  this->imag(w.imag()); }
  inline double dot(Point p){ return (conj(*this) * p).real(); }  // ??????
  inline double det(Point p){ return (conj(*this) * p).imag(); }  // ??????
};

namespace std
{
  inline bool operator < (const Point& a, const Point& b)
  {
    return real(a) != real(b) ? real(a) < real(b) : imag(a) < imag(b);
  }
}
typedef vector<Point> Polygon;
inline Point currPoint(vector<Point> P, int i){ return P[i]; }
inline Point nextPoint(vector<Point> P, int i){ return P[(i+1)%P.size()]; }
inline Point diffPoint(vector<Point> P, int i){ return nextPoint(P, i) - currPoint(P, i); }

int ccw(Point a, Point b, Point c)
{
  b -= a;
  c -= a;
  if(b.det(c) > 0.0)    return  1;         // counter clockwise
  if(b.det(c) < 0.0)    return -1;         // clockwise
  if(b.dot(c) < 0.0)    return  2;         // c--a--b on line
  if(norm(b) < norm(c)) return -2;         // a--b--c on line
  return 0;
}


struct Circle : Point
{
private:
  Point p;
  double r;

public:
  Circle(Point p, double r) : p(p), r(r) {}
  Circle(double x, double y, double r) : p(Point(x, y)), r(r) {}
  inline Point center(){ return this->p; }
  inline double radius(){ return this->r; }
};


int intersectionDeterminationOfCC(Circle A, Circle B)
{
  double d = abs(A.center() - B.center());
  if(semile(d, A.radius() - B.radius())) return  1;  // B in A
  if(semile(d, B.radius() - A.radius())) return -1;  // A in B
  if(semieq(d, A.radius() - B.radius())) return  2;  // B in A????????\???
  if(semieq(d, B.radius() - A.radius())) return -2;  // A in B????????\???
  if(semige(d, A.radius() + B.radius())) return  3;  // ???????????????
  if(semieq(d, A.radius() + B.radius())) return -3;  // ?????\
  return 4;  // ????????£?????????
}


// ???????????????????¨±??????????????????????????????????????¨????????????????¨???????????????????
inline vector<Point> intersectionOfCCk(Circle A, Circle B)
{
  vector<Point> ret(2);
  double d = abs(add(A.center(), -B.center()));
  double rc = (add(add(d * d, A.radius() * A.radius()), -B.radius() * B.radius()));
  double rs = sqrt(add(A.radius() * A.radius(), - rc * rc / (4.0 * d * d)));
  Point diff = (add(B.center(), -A.center()));
  ret[0] = add(A.center(), diff * Point(rc / (2.0 * d * d), ( rs / d)));
  ret[1] = add(A.center(), diff * Point(rc / (2.0 * d * d), (-rs / d)));
  return ret;
}

vector<Point> intersectionOfCC(Circle A, Circle B)
{
  vector<Point> ret(2);
  double x1 = A.center().real(), y1 = A.center().imag(), r1 = A.radius();
  double x2 = B.center().real(), y2 = B.center().imag(), r2 = B.radius();
  double dx = x2 - x1;
  double dy = y2 - y1;
  double a = dx * dx + dy * dy;
  double b = ((r1 * r1 - r2 * r2) / a + 1) / 2;
  double d = r1 * r1 / a - b * b;
  double x3 = x1 + dx * b;
  double y3 = y1 + dy * b;
  double x4 = -dy * sqrt(d);
  double y4 =  dx * sqrt(d);
  ret[0] = Point(x3 - x4, y3 - y4);
  ret[1] = Point(x3 + x4, y3 + y4);
  return ret;
}

int n;
double x, y;
Point P[33333];
bool maze[5010][5010];

int main()
{
  while(cin >> n, n){
    rep(i, 5010) rep(j, 5010) maze[i][j] = false;
    rep(i, n){
      cin >> x >> y;
      maze[(int)x][(int)y] = true;
      P[i] = Point(x, y);
    }

    double res = 0.0;
    rep(i, n) rep(j, i){
      double len = abs(P[i] - P[j]) * sqrt(2.0) / 2.0;
      vector<Point> can = intersectionOfCC(Circle(P[i], len), Circle(P[j], len));
      int flag = 0;
      vrep(c, can) if(!semile(c->real(), 0.0) && !semile(c->imag(), 0.0)){
        if(!semieq(c->real(), round(c->real()))) break;
        if(!semieq(c->imag(), round(c->imag()))) break;
        if((int)round(c->real()) >= 5005 || (int)round(c->imag()) >= 5005) break;
        if(!maze[(int)round(c->real())][(int)round(c->imag())]) break;
        flag += 1;
      }
      if(flag == 2) maxup(res, len * len);
    }

    cout << (int)round(res) << endl;
  }

  return 0;
}

Measured memory_bytes: 26288