#include<bits/stdc++.h>
#define int long long
using namespace std;
const double pi=3.14159;
int n,ans;
struct vec{
	int x,y;double a;
	vec friend operator+(vec a,vec b){
		return {a.x+b.x,a.y+b.y};
	}
	bool friend operator==(vec a,vec b){
		return a.x==b.x&&a.y==b.y;
	}
	vec friend operator-(vec a,vec b){
		return {a.x-b.x,a.y-b.y};
	}
	int norm(){
		return x*x+y*y;
	}
	int det(vec b){
		return x*b.y-y*b.x;
	}
	int dot(vec b){
		return x*b.x+y*b.y;
	}
	int get(){
		return y>0||(y==0&&x>=0);
	}
	double angle(){
		return atan2(y,x)+(atan2(y,x)<0)*pi*2;
	}
}v[600005];
bool cmp(vec a,vec b){
	if(a.get()==b.get())return a.det(b)>0||(a.det(b)==0&&a.norm()<b.norm());
	return a.get()>b.get();
	//return a.angle()<b.angle();
}
signed main(){
	scanf("%lld",&n);
	for(int i=1;i<=n;i++)scanf("%lld%lld",&v[i].x,&v[i].y);
	sort(v+1,v+n+1,cmp);
	for(int i=1;i<=n;i++)v[i+n]=v[i],v[i].a=v[i].angle(),v[i+n].a=v[i].a+pi*2;
	vec now=v[0];
	for(int l=1,r=0;l<=n;l++){
		now=now-v[l-1];ans=max(ans,now.norm());
		while(r+1<l+n&&v[r+1].a-v[l].a<=pi)now=now+v[++r],ans=max(ans,now.norm());
		//cout<<l<<" "<<r<<" "<<now.norm()<<endl;
	}
	printf("%lld",ans);
}