#include<cstdio>
#include<algorithm>
namespace IO{
	char buf[1<<15],*fs,*ft;
	inline char gc(){return (fs==ft&&(ft=(fs=buf)+fread(buf,1,1<<15,stdin),fs==ft))?0:*fs++;}
	inline int qr(){
		int x=0,ch=gc();
		while(ch<'0'||ch>'9'){ch=gc();}
		while(ch>='0'&&ch<='9'){x=(x<<1)+(x<<3)+ch-'0';ch=gc();}
		return x;}
}using namespace IO;
using namespace std;
/***********************************************************************************************/
struct E{
	int x;
	int y;
	int len;
}e[1000010];
struct C{
	int x;
	int y;
}c[1010];
int f[1010],n,t=0;
void memset(){
	for(int i=0;i<=n;i++){
		f[i]=i;}}
int findf(int x){
	if(x==f[x]){
		return f[x];}
	return f[x]=findf(f[x]);}
void merge(int x,int y){
	int xx=findf(x);
	int yy=findf(y);
	if(xx!=yy){
		f[xx]=yy;}}
bool cmp(E x,E y){
	return x.len<y.len;}
void kruskal(){
	int k=0,ans=0;
	sort(e,e+t,cmp);
	for(int i=0;i<t;i++){
		if(k>n-1){
			break;}
		if(findf(e[i].x)!=findf(e[i].y)){
			k++;
			ans=max(ans,e[i].len);
			merge(e[i].x,e[i].y);}}
	printf("%d",ans);}
int sb(){
	freopen ("moocast.in","r",stdin);
	freopen ("moocast.out","w",stdout);
	int i,j;
	n=qr();
	for(i=1;i<=n;i++){
		c[i].x=qr();
		c[i].y=qr();}
	for(i=1;i<=n;i++){
		for(j=1;j<i;j++){
			e[t].x=i;
			e[t].y=j;
			e[t].len=(c[i].x-c[j].x)*(c[i].x-c[j].x)+(c[i].y-c[j].y)*(c[i].y-c[j].y);
			t++;}}
	memset();
	kruskal();
	return 0;
}
int chh=sb();
int main(){
	return 0;
}