#include <bits/stdc++.h>
using namespace std;
#define int long long
vector<int> tree;
int fin(int n) {
if (tree[n] == n) return n;
return tree[n] = fin(tree[n]);
}
void join(int a, int b) {
a = fin(a);
b = fin(b);
if (a == b) return;
tree[b] = a;
}
long double dist(pair<long double, long double> a, pair<long double, long double> b) {
return pow((a.first - b.first) * (a.first - b.first) + (a.second - b.second) * (a.second - b.second), (long double)0.5);
}
signed main() {
int n, x, y;
cin >> n;
vector<pair<int, int>> coords;
for (int i = 0; i < n; i++) {
cin >> x >> y;
coords.push_back({ x, y });
}
priority_queue<pair<long double, pair<int, int>>, vector<pair<long double, pair<int, int>>>, greater<pair<long double, pair<int, int>>>> pq;
for (int i = 0; i < n; i++) {
for (int j = i + 1; j < n; j++) {
pair<long double, long double> midpoint = { (coords[i].first + coords[j].first) / 2, (coords[i].second + coords[j].second) / 2 };
pair<int, int> lattice = { 0, 0 };
long double crntmin = 1e10;
for (int k = 0; k < 2; k++) {
for (int l = 0; l < 2; l++) {
if (dist(midpoint, { (int)midpoint.first + k, (int)midpoint.second + l }) < crntmin) {
crntmin = dist(midpoint, { (int)midpoint.first + k, (int)midpoint.second + l });
lattice = { (int)midpoint.first + k, (int)midpoint.second + l };
}
}
}
long double dist1 = dist(coords[i], lattice);
long double dist2 = dist(coords[j], lattice);
pq.push({ (dist1 + dist2) / 2, {i, j} });
}
}
for (int i = 0; i < n; i++)
tree.push_back(i);
long double ans = 0;
while (!pq.empty()) {
if (fin(pq.top().second.first) != fin(pq.top().second.second)) {
ans = max(ans, pq.top().first);
join(pq.top().second.first, pq.top().second.second);
}
pq.pop();
}
cout << ans << '\n';
}
