#include <bits/stdc++.h>
using namespace std;
#define int long long
typedef pair<int,int> ii;
typedef pair<int,ii> dii;
int dist(ii a, ii b){
return (int)(pow(((a.first-b.first)*(a.first-b.first)+(a.second-b.second)*(a.second-b.second)),0.5)*1e9);
}
vector<int> ufds;
int search(int p){
if(ufds[p]==-1){
return p;
}
return ufds[p] = search(ufds[p]);
}
void join(int a, int b){
ufds[search(a)] = search(b);
}
signed main(){
int n;
cin>>n;
vector<ii> antenna(n,ii());
ufds = vector<int> (n,-1);
for (int i=0;i<n;++i){
cin>>antenna[i].first>>antenna[i].second;
}
priority_queue<dii,vector<dii>,greater<dii>> mst;
for(int i=0;i<n;++i){
for (int j=i+1;j<n;++j){
if(i!=j) mst.push(dii(dist(antenna[i],antenna[j]),ii(i,j)));
}
}
double max_dist = 0;
while(!mst.empty()){
auto curr = mst.top();
mst.pop();
double dist=curr.first;
int a = curr.second.first, b = curr.second.second;
if(search(a)==search(b)) continue;
join(a,b);
max_dist = max(max_dist, dist);
}
cout<<fixed;
cout<<setprecision(9);
cout<<max_dist/2000000000;
}
