#include <bits/stdc++.h>
typedef long long ll;
using namespace std;
pair<int, int> p[1000];
vector<tuple<double, int, int>> edges;
int n, cmp[1000];
int find(int A) {
while (cmp[A] != A) cmp[A] = cmp[cmp[A]], A = cmp[A];
return A;
}
void onion(int A, int B) {
if (find(A) != find(B)) n--;
cmp[find(A)] = find(B);
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n;
for (int i = 0; i < n; i++) {
cin >> p[i].first >> p[i].second;
for (int j = 0; j < i; j++) {
edges.push_back({hypot(p[i].first - p[j].first, p[i].second - p[j].second), i, j});
}
}
sort(edges.begin(), edges.end());
iota(cmp, cmp + n, 0);
for (tuple<double, int, int> i : edges) {
double cost;
int a, b;
tie(cost, a, b) = i;
onion(a, b);
if (n == 1) return cout << fixed << setprecision(8) << cost / 2, 0;
}
return 0;
}
