// includes
#include <bits/stdc++.h>
using namespace std;

// macros
#define pb emplace_back
#define mk make_pair
#define FOR(i, a, b) for(int i=(a);i<(b);++i)
#define rep(i, n) FOR(i, 0, n)
#define rrep(i, n) for(int i=((int)(n)-1);i>=0;i--)
#define irep(itr, st) for(auto itr = (st).begin(); itr != (st).end(); ++itr)
#define irrep(itr, st) for(auto itr = (st).rbegin(); itr != (st).rend(); ++itr)
#define whole(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end())
#define bit(n) (1LL<<(n))
// functions
template <class T>bool chmax(T &a, const T &b){if(a < b){a = b; return 1;} return 0;}
template <class T>bool chmin(T &a, const T &b){if(a > b){a = b; return 1;} return 0;}
template <typename T> istream &operator>>(istream &is, vector<T> &vec){for(auto &v: vec)is >> v; return is;}
template <typename T> ostream &operator<<(ostream &os, const vector<T>& vec){for(int i = 0; i < vec.size(); i++){ os << vec[i]; if(i + 1 != vec.size())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const set<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const unordered_set<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const multiset<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const unordered_multiset<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &p){os << p.first << " " << p.second; return os;}
template <typename T1, typename T2> ostream &operator<<(ostream &os, const map<T1, T2> &mp){for(auto itr = mp.begin(); itr != mp.end(); ++itr){ os << itr->first << ":" << itr->second; auto titr = itr; if(++titr != mp.end())os << " "; } return os;}
template <typename T1, typename T2> ostream &operator<<(ostream &os, const unordered_map<T1, T2> &mp){for(auto itr = mp.begin(); itr != mp.end(); ++itr){ os << itr->first << ":" << itr->second; auto titr = itr; if(++titr != mp.end())os << " "; } return os;}
//  types
using ll = long long int;
using P = pair<int, int>;
// constants
const int inf = 1e9;
const ll linf = 1LL << 50;
const double EPS = 1e-10;
const int mod = 1000000007;
const int dx[4] = {-1, 0, 1, 0};
const int dy[4] = {0, -1, 0, 1};
// io
struct fast_io{
  fast_io(){ios_base::sync_with_stdio(false); cin.tie(0); cout << fixed << setprecision(20);}
} fast_io_;

using ld = long double;

int main(int argc, char const* argv[])
{
  int n; cin >> n;
  vector<ld> x(n), y(n); rep(i, n)cin >> x[i] >> y[i];
  ld rmax = 0.;
  rep(i, n){
    FOR(j, i + 1, n){
      ld r = hypot(x[i] - x[j], y[i] - y[j]) / 2.;
      rmax = max(rmax, r);
    }
  }
  ld l = rmax, r = rmax * 2.;
  //cerr << l << " " << r << endl;
  rep(i_, 100){
    ld m = (l + r) / 2.;
    bool ok = false;
    auto check = [&](ld X, ld Y) -> bool{
      rep(k, n){
        ld dis = hypot(X - x[k], Y - y[k]);
        if(dis > m + EPS)return false;
      }
      return true;
    };
    rep(i, n){
      FOR(j, i + 1, n){
        ld X1 = x[j] - x[i], Y1 = y[j] - y[i];
        ld a = (X1 * X1 + Y1 * Y1) / 2.;
        //cerr << X1 << " " << Y1 << " " << m << " " << (X1 * X1 + Y1 * Y1) * m * m - a * a << endl;
        ld ex1 = (a * X1 + Y1 * sqrt(EPS + (X1 * X1 + Y1 * Y1) * m * m - a * a)) / (X1 * X1 + Y1 * Y1);
        ld ey1 = (a * Y1 - X1 * sqrt(EPS + (X1 * X1 + Y1 * Y1) * m * m - a * a)) / (X1 * X1 + Y1 * Y1);
        ld ex2 = (a * X1 - Y1 * sqrt(EPS + (X1 * X1 + Y1 * Y1) * m * m - a * a)) / (X1 * X1 + Y1 * Y1);
        ld ey2 = (a * Y1 + X1 * sqrt(EPS + (X1 * X1 + Y1 * Y1) * m * m - a * a)) / (X1 * X1 + Y1 * Y1);
        // cerr << m << " " << ex1 << " " << ey1 << endl;
        // cerr << m << " " << ex2 << " " << ey2 << endl;
        ex1 += x[i], ex2 += x[i];
        ey1 += y[i], ey2 += y[i];
        if(check(ex1, ey1))ok = true;
        if(check(ex2, ey2))ok = true;
        ld ex3 = (x[i] + x[j]) / 2., ey3 = (y[i] + y[j]) / 2.;
        if(check(ex3, ey3))ok = true;
      }
    }
    if(ok)r = m;
    else l = m;
  }
  cout << r << endl;
  return 0;
}


Measured memory_bytes: 384