#include<bits/stdc++.h>
using namespace std;
int main(){
int n;
cin>>n;
vector<pair<long double,long double>>v(n);
for(int i = 0;i<n;i++){
long double a,b;cin>>a>>b;
v[i]={a,b};
}
long double ma = 0.0;
for(int i = 0;i<n;i++){
long double mi = 1e9;
for(int j =0;j<n;j++){
if(i==j)continue;
long double a = abs(v[i].first-v[j].first)*abs(v[i].first-v[j].first) , b= abs(v[i].second-v[j].second)*abs(v[i].second-v[j].second);
long double r = (sqrt(a+b))/2.0;
mi = min(mi,r);
}
ma = max(ma,mi);
}
cout<<setprecision(9)<<fixed<<ma;
return 0;
}
