#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define int long long
#define ll long long
#define ull unsigned long long
#define lb lower_bound
#define ub upper_bound
#define IOS ios::sync_with_stdio(false), cin.tie(0), cout.tie(0)
void solve() {
int n;
cin >> n;
vector<pair<int, int>> vt;
for (int i = 1; i <= n; i++){
int a, b;
cin >> a >> b;
vt.push_back({a, b});
}
double l = 0.0, r = 1e6, best = 0.0;
for(int times = 1; times <= 100; times++){
double m = (l + r) / 2 * 1.0;
vector<int> adj[n + 5];
for (int i = 1; i <= n; i++){
for (int j = i + 1; j <= n; j++){
pair<int, int> p1 = vt[i - 1], p2 = vt[j - 1];
if(sqrt(abs(p1.first - p2.first)*abs(p1.first - p2.first) + abs(p1.second - p2.second)*abs(p1.second - p2.second)) / 2 <= m){
adj[i].push_back(j);
adj[j].push_back(i);
}
}
}
int dis[n + 5];
memset(dis, -1, sizeof(dis));
queue<int> q;
q.push(1);
dis[1] = 0;
while(q.size()){
int x = q.front();
q.pop();
for(int i : adj[x]){
if(dis[i] == -1){
q.push(i);
dis[i] = dis[x] + 1;
}
}
}
bool ok = true;
for (int i = 1; i <= n; i++)if(dis[i] == -1)ok = false;
if(ok){
r = m;
best = m;
}
else l = m;
}
cout << setprecision(10) << fixed << best << endl;
}
signed main() {
IOS;
int t = 1;
//cin >> t;
while (t--) {
solve();
}
}
