#include <bits/stdc++.h>
using namespace std;
const int N = 3000 + 11;
const int MOD = 1e9 + 7;
int a[N], b[N];
bitset<N> c[N];
int n;
int dist(int l, int r) {
  return (a[l] - a[r]) * (a[l] - a[r]) + (b[l] - b[r]) * (b[l] - b[r]);
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cout.precision(8);
  cout << fixed;
  cin >> n;
  for (int i = 1; i <= n; i++) cin >> a[i] >> b[i];
  vector<pair<int, pair<int, int> > > vv;
  for (int i = 1; i <= n; i++)
    for (int j = i + 1; j <= n; j++)
      vv.push_back(make_pair(dist(i, j), make_pair(i, j)));
  sort(vv.begin(), vv.end());
  for (int j = vv.size() - 1; j >= 0; j--) {
    int l = vv[j].second.first, r = vv[j].second.second;
    if ((c[l] & c[r]).count() > 0) {
      cout << (long double)sqrt((long double)vv[j].first) / (long double)2;
      exit(0);
    }
    c[l][r] = 1;
    c[r][l] = 1;
  }
  cout << 0;
}
