/**
* بسم الله الرحمن الرحيم *
﴾ رَبِّ اشْرَحْ لِي صَدْرِي * وَيَسِّرْ لِي أَمْرِي * وَاحْلُلْ عُقْدَةً مِّن لِّسَانِي * يَفْقَهُوا قَوْلِي ﴿
*/
/// author : "ASGA_RedSea"
#include <bits/stdc++.h>
using namespace std;
#ifdef ONLINE_JUDGE
#define endl '\n'
#endif
using ll = long long;
using ld = long double;
using ull = unsigned long long;
const ll mod = 1000000007;
ld m,e = 1e-7;
int n;
vector <pair <ld,ld>> a;
vector <int> v;
void calc(int i){
v[i] = 1;
for(int j = 0;j < n;j++){
if(v[j])continue;
if(sqrt(pow(abs(a[i].first - a[j].first),2.0) + (pow(abs(a[i].second - a[j].second),2.0))) - (m * 2.0) <= e)calc(j);
}
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout << fixed << setprecision(6);
///cout.tie(0);
///freopen("test.in", "r", stdin);
///freopen("test.out", "w", stdout);
cin >> n;
a.resize(n);
for(auto& i : a)cin >> i.first >> i.second;
ld l = 0.00000000,r = 2000000000.00000000;
while(r - l >= e){
m = (l + r) / 2;
int f = 1;
v = vector <int> (n,0);
calc(0);
for(int i = 1;i < n && f;i++){
if(v[i] == 0)f = 0;
}
if(f)r = m - e;
else l = m + e;
}
cout << l << endl;
return 0;
}
