// TEMPLATE
#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ordered_set tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>
#define ordered_set_char tree<char, null_type, less<char>, rb_tree_tag, tree_order_statistics_node_update>
#define ordered_set_string tree<string, null_type, less<string>, rb_tree_tag, tree_order_statistics_node_update>
#define ordered_multiset tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update>
#define ordered_multiset_char tree<char, null_type, less_equal<char>, rb_tree_tag, tree_order_statistics_node_update>
#define ordered_multiset_string tree<string, null_type, less_equal<string>, rb_tree_tag, tree_order_statistics_node_update>
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
// #define int long long
#define ldouble long double
#define ll unsigned long long
// #define int int_fast32_t
#define endl '\n'
#define pii pair<int, int>
#define F first
#define S second
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 = 1e15, ans = 0.0;
for (int k = 1; k <= 105; k++)
{
double d = 1.0 * (l + r) / 2;
vector<int> adj[n + 5];
for (int i = 1; i <= n; i++)
{
for (int j = i + 1; j <= n; j++)
{
pii o = vt[i - 1], p = vt[j - 1];
if (sqrt(abs(o.first - p.first) * abs(o.first - p.first) + abs(o.second - p.second) * abs(o.second - p.second)) / 2 <= d)
{
adj[i].push_back(j);
adj[j].push_back(i);
}
}
}
vector<int> dis(n + 5, -1);
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)
{
ans = d;
r = d;
}
else
{
l = d;
}
}
cout << setprecision(7) << fixed << ans << endl;
}
signed main()
{
ios::sync_with_stdio(false);
cin.tie(0);
int T = 1;
// cin >> T;
while (T--)
solve();
}
