#include <bits/stdc++.h>
using namespace std;
constexpr int N=5e4+5;
int n;
mt19937 rnd(time(0));
struct P{
	long double x,y;
	long double len()const{
		return sqrt(x*x+y*y);
	}
}a[N];
long double dis(const P &a,const P &b){
	long double dx{a.x-b.x},dy{a.y-b.y};
	return dx*dx+dy*dy;
}
void rotate(P &p,long double r){
	long double len=p.len(),r0=atan2(p.x,p.y);
	r0+=r;
	p.x=len*cos(r0),p.y=len*sin(r0);
}
int main(){
	cin.tie(0)->sync_with_stdio(0);
	cin>>n;
	for(int i{1};i<=n;++i) cin>>a[i].x>>a[i].y;
	int t=20;
	uniform_real_distribution<> dist(100.0);
	long double ans{0.0};
	while(t--){
		long double r=dist(rnd);
		for(int i{1};i<=n;++i) rotate(a[i],r);
		sort(a+1,a+n+1,[](const P &a,const P &b){return a.x<b.x;});
		for(int i{1};i<=100&&i<=n;++i) for(int j{n};j>n-100&&j>=1;--j)
			ans=max(ans,dis(a[i],a[j]));
	}
	printf("%.7Lf\n",sqrtl(ans));
	return 0;
}