#include<bits/stdc++.h>
using namespace std;
#define nl '\n'
#define ll long long
const int N = 1e5+5;
ll a[N], b[N];
ll dis(ll x, ll y, ll xx, ll yy){
return ((x-xx)*(x-xx)+(y-yy)*(y-yy));
}
int main() {
int n; cin >> n;
for(int i=0;i<n;++i) cin >> a[i] >> b[i];
ll d = -1.0;
for(int i=0;i<n;++i){
for(int j=0;j<n;++j){
d = max(d, dis(a[i], b[i], a[j], b[j]));
// cerr << d << endl;
}
}
double l = 0;
double r = 1e7;
double ans = 0;
int t = 100;
while(t--){
double mid = (l+r)/2;
if(mid*mid<=d) ans = mid, l = mid;
else r = mid;
}
cout << fixed << setprecision(10) << ans / 2.0l<< nl;
}