// May this submission get accepted
#pragma GCC optimize ("O3")

#include <bits/stdc++.h>

// 汎用マクロ
#define ALL_OF(x) (x).begin(), (x).end()
#define REP(i,n) for (long long i=0, i##_len=(n); i<i##_len; i++)
#define RANGE(i,is,ie) for (long long i=(is), i##_end=(ie); i<=i##_end; i++)
#define DSRNG(i,is,ie) for (long long i=(is), i##_end=(ie); i>=i##_end; i--)
#define STEP(i, is, ie, step) for (long long i=(is), i##_end=(ie), i##_step = (step); i<=i##_end; i+=i##_step)
#define UNIQUE(v) do { sort((v).begin(), (v).end()); (v).erase(unique((v).begin(), (v).end()), (v).end()); } while (false)
template<class T> bool chmax(T &a, const T &b) { if (a < b) {a = b; return true;} return false; }
template<class T> bool chmin(T &a, const T &b) { if (a > b) {a = b; return true;} return false; }
#define INF 0x7FFFFFFF
#define LINF 0x7FFFFFFFFFFFFFFFLL
#define Yes(q) ((q) ? "Yes" : "No")
#define YES(q) ((q) ? "YES" : "NO")
#define Possible(q) ((q) ? "Possible" : "Impossible")
#define POSSIBLE(q) ((q) ? "POSSIBLE" : "IMPOSSIBLE")
#define DUMP(q) cerr << "[DEBUG] " #q ": " << (q) << " at " __FILE__ ":" << __LINE__ << endl
#define DUMPALL(q) do { cerr << "[DEBUG] " #q ": ["; REP(DUMPALL_ITR, (q).size()) { cerr << (q)[DUMPALL_ITR] << (DUMPALL_ITR == DUMPALL_ITR_len-1 ? "" : ", "); } cerr << "] at " __FILE__ ":" << __LINE__ << endl; } while (false)
template<class T> T gcd(T a, T b) { if (a < b) std::swap(a, b); while (b) std::swap(a %= b, b); return a; }
template<class T> T lcm(const T a, const T b) { return a / gcd(a, b) * b; }

// gcc拡張マクロ
#define popcount __builtin_popcount
#define popcountll __builtin_popcountll

// エイリアス
#define DANCE_ long
#define ROBOT_ unsigned
#define HUMAN_ signed
using  ll = DANCE_ HUMAN_ DANCE_;
using ull = DANCE_ ROBOT_ DANCE_;
using  ld = long double;
using namespace std;

// 標準入出力
struct inp {
    size_t sz;
    inp(size_t _sz = 1) : sz(_sz) {}
    template <typename T> operator T () const { T a; cin >> a; return a; }
    template <typename T> operator vector<T> () const { vector<T> a(sz); for (size_t i = 0; i < sz; i++) cin >> a[i]; return a; }
    template <typename T, typename U> operator pair<T, U> () const { T f; U s; cin >> f >> s; return pair<T, U>(f, s); }
};
inp inp1; // input one
template <typename T> void say(T &x, char end = '\n') { cout << x << end; }
template <typename T> void say(vector<T> &x, char sep = ' ', char end = '\n') { for (size_t i = 0, sz = x.size(); i < sz; i++) { cout << x[i] << (i == sz-1 ? end : sep); } }

// モジュール

constexpr ll dim = 2;
using point = vector<ld>;
using number = ld;

number dist2(const point &a, const point &b) {
    return (a[0] - b[0]) * (a[0] - b[0]) + (a[1] - b[1]) * (a[1] - b[1]);
}

point addp(const point &a, const point &b) {
    return {a[0] + b[0], a[1] + b[1]};
}

point subt(const point &a, const point &b) {
    return {a[0] - b[0], a[1] - b[1]};
}

point sprod(const number a, const point &b) {
    return {b[0] * a, b[1] * a};
}

number dot(const point &a, const point &b) {
    return a[0] * b[0] + a[1] * b[1];
}

// 引用元: http://www.prefield.com/algorithm/geometry3D/min_ball.html
struct min_ball {
  point center;
  number radius2;
  void add(const point& p) {
    ps.push_back(p);
  }
  void compile() {
    m = 0;
    center.resize(dim, 0);
    radius2 = -1;
    make_ball(ps.end());
  }
  template <class OUT>
  void support(OUT out) {
    copy(ps.begin(), supp_end, out);
  }
  min_ball() {
    for (int i = 0; i <= dim; ++i) {
      c[i].resize(dim, 0);
      v[i].resize(dim, 0);
    }
  }
private:
  list<point> ps;
  list<point>::iterator supp_end;
  int m;
  point v[dim+1], c[dim+1];
  number z[dim+1], r[dim+1];
  void pop() { --m; }
  void push(const point& p) {
    if (m == 0) {
      c[0] = p; r[0] = 0;
    } else {
      number e = dist2(p, c[m-1]) - r[m-1];
      point delta = subt(p, c[0]);
      v[m] = subt(p, c[0]);
      for (int i = 1; i < m; ++i) {
        auto s = sprod(dot(v[i], delta) / z[i], v[i]);
        auto t = subt(v[m], s);
        v[m] = t;
      }
      z[m] = dot(v[m], v[m]);
      c[m] = addp(c[m-1], sprod(e/z[m]/2, v[m]));
      r[m] = r[m-1] + e*e/z[m]/4;
    }
    center  = c[m];
    radius2 = r[m]; ++m;
  }
  void make_ball(list<point>::iterator i) {
    supp_end = ps.begin();
    if (m == dim + 1) return;
    for (list<point>::iterator k = ps.begin(); k != i; ) {
      list<point>::iterator j = k++;
      if (dist2(*j, center) > radius2) {
        push(*j); make_ball(j); pop();
        move_to_front(j);
      }
    }
  }
  void move_to_front(list<point>::iterator j) {
    if (supp_end == j) ++supp_end;
    ps.splice (ps.begin(), ps, j);
  }
};
// 引用終わり

// 処理内容
int main() {
    
    ios::sync_with_stdio(false); // stdioを使うときはコメントアウトすること
    cin.tie(nullptr);            // インタラクティブ問題ではコメントアウトすること
    
    ll n = inp1;
    vector<point> p(n);
    REP(i, n) {
        ld x, y;
        cin >> x >> y;
        p[i] = {x, y};
    }

    min_ball mb;
    REP(i, n) {
        mb.add(p[i]);
    }
    mb.compile();

    cout << fixed << setprecision(20) << sqrtl(mb.radius2) << endl;

    
}

Measured memory_bytes: 256