// 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(); }