#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  vector<int> x(n), y(n);
  for (int i = 0; i < n; ++i) {
    cin >> x[i] >> y[i];
  }
  vector<bitset<3000> > d(n);
  vector<pair<int, pair<int, int> > > a;
  for (int i = 0; i < n; ++i) {
    for (int j = i + 1; j < n; ++j) {
      a.push_back(
          {(x[i] - x[j]) * (x[i] - x[j]) + (y[i] - y[j]) * (y[i] - y[j]),
           {i, j}});
    }
  }
  sort(a.begin(), a.end());
  reverse(a.begin(), a.end());
  for (int i = 0; i < a.size(); ++i) {
    int a1 = a[i].second.first, a2 = a[i].second.second;
    if ((d[a1] & d[a2]).any()) {
      cout.precision(10);
      cout << fixed;
      cout << sqrt(a[i].first + .0) / 2.0 << endl;
      return 0;
    }
    d[a1].set(a2);
    d[a2].set(a1);
  }
}
