#include <bits/stdc++.h>
#define LLI long long int
#define FOR(v, a, b) for(LLI v = (a); v < (b); ++v)
#define FORE(v, a, b) for(LLI v = (a); v <= (b); ++v)
#define REP(v, n) FOR(v, 0, n)
#define REPE(v, n) FORE(v, 0, n)
#define REV(v, a, b) for(LLI v = (a); v >= (b); --v)
#define ALL(x) (x).begin(), (x).end()
#define RALL(x) (x).rbegin(), (x).rend()
#define ITR(it, c) for(auto it = (c).begin(); it != (c).end(); ++it)
#define RITR(it, c) for(auto it = (c).rbegin(); it != (c).rend(); ++it)
#define EXIST(c,x) ((c).find(x) != (c).end())
#define fst first
#define snd second
#define popcount __builtin_popcount
#define UNIQ(v) (v).erase(unique(ALL(v)), (v).end())
#define bit(i) (1LL<<(i))

#ifdef DEBUG
#include <misc/C++/Debug.cpp>
#else
#define dump(...) ((void)0)
#endif

#define gcd __gcd

using namespace std;
template <class T> constexpr T lcm(T m, T n){return m/gcd(m,n)*n;}

template <typename I> void join(ostream &ost, I s, I t, string d=" "){for(auto i=s; i!=t; ++i){if(i!=s)ost<<d; ost<<*i;}ost<<endl;}
template <typename T> istream& operator>>(istream &is, vector<T> &v){for(auto &a : v) is >> a; return is;}
template <typename T, typename U> bool chmin(T &a, const U &b){return (a>b ? a=b, true : false);}
template <typename T, typename U> bool chmax(T &a, const U &b){return (a<b ? a=b, true : false);}
template <typename T, size_t N, typename U> void fill_array(T (&a)[N], const U &v){fill((U*)a, (U*)(a+N), v);}

struct Init{
  Init(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(12);
    cerr << fixed << setprecision(12);
  }
}init;

#define double long double


constexpr double eps = 1e-9;

template <typename T, typename U> bool EQ(const T &a, const U &b){return std::fabs(a-b) < eps;}
template <typename T, typename U> bool NE(const T &a, const U &b){return not EQ(a,b);}
template <typename T, typename U> bool LT(const T &a, const U &b){return a-b < -eps;}
template <typename T, typename U> bool LE(const T &a, const U &b){return a-b < eps;}
template <typename T, typename U> bool GT(const T &a, const U &b){return not LE(a,b);}
template <typename T, typename U> bool GE(const T &a, const U &b){return not LT(a,b);}

template <typename T> struct Point{
  T x, y;
  Point(): x(0), y(0){}
  Point(const T &x, const T &y): x(x), y(y){}
  T size() const {return sqrt(x*x+y*y);}
  T size_sq() const {return x*x+y*y;}
  
  static Point<T> polar(const T &r, const T &ang){return Point(r * cos(ang), r * sin(ang));}
};

template <typename T> Point<T> operator+(const Point<T> &a, const Point<T> &b){return Point<T>(a.x+b.x, a.y+b.y);}
template <typename T> Point<T> operator-(const Point<T> &a, const Point<T> &b){return Point<T>(a.x-b.x, a.y-b.y);}
template <typename T> Point<T> operator-(const Point<T> &a){return Point<T>(-a.x, -a.y);}
template <typename T, typename U> Point<T> operator*(const Point<T> &a, const U &k){return Point<T>(a.x*k, a.y*k);}
template <typename T, typename U> Point<T> operator*(const U &k, const Point<T> &a){return Point<T>(a.x*k, a.y*k);}
template <typename T, typename U> Point<T> operator/(const Point<T> &a, const U &k){return Point<T>(a.x/k, a.y/k);}
template <typename T> bool operator==(const Point<T> &a, const Point<T> &b){return EQ(a.x,b.x) and EQ(a.y,b.y);}
template <typename T> bool operator!=(const Point<T> &a, const Point<T> &b){return !(a==b);}
template <typename T> bool operator<(const Point<T> &a, const Point<T> &b){return LT(a.x,b.x) or (EQ(a.x,b.x) and LT(a.y,b.y));}
template <typename T> std::istream& operator>>(std::istream &is, Point<T> &a){is >> a.x >> a.y; return is;}
template <typename T> std::ostream& operator<<(std::ostream &os, const Point<T> &a){os << "(" << a.x << "," << a.y << ")"; return os;}
template <typename T> T dot(const Point<T> &a, const Point<T> &b){return a.x*b.x+a.y*b.y;}
template <typename T> T cross(const Point<T> &a, const Point<T> &b){return a.x*b.y-a.y*b.x;}
template <typename T> T angle(const Point<T> &a, const Point<T> &b){return atan2(b.y-a.y, b.x-a.x);} // 点aから点bへの角度
template <typename T> Point<T> unit(const Point<T> &a){return a / a.size();} // 単位ベクトル
template <typename T> Point<T> normal(const Point<T> &p){return Point<T>(-p.y,p.x);}
template <typename T> T phase(const Point<T> &a){return std::atan2(a.y, a.x);}

template <typename T>
T angle_diff(const Point<T> &a, const Point<T> &b){
  T r = phase(b) - phase(a);

  if(r < -M_PI) return r + 2 * M_PI;
  else if(r > M_PI) return r - 2 * M_PI;
  return r;
}

template <typename T> struct Line{
  Point<T> from, to;
  Line(): from(), to(){}
  Line(const Point<T> &from, const Point<T> &to): from(from), to(to){}
  Point<T> diff() const {return to-from;}
  T size() const {return diff().size();}
};

template <typename T> using Segment = Line<T>;
template <typename T> using Polygon = std::vector<Point<T>>;

template <typename T> struct Circle{
  Point<T> center;
  T radius;
  Circle(): center(), radius(0){}
  Circle(const Point<T> &center, T radius): center(center), radius(radius){}
};


/**
 * @brief 下に凸の三分探索
 */
template <typename T, typename Func>
T ternary_search_downwards(T lb, T ub, const Func &f){
  int LOOP_COUNT = 400;
  T t1,t2;
  
  while(LOOP_COUNT--){
    t1 = lb+(ub-lb)/3;
    t2 = lb+(ub-lb)/3*2;
    
    if(f(t1) < f(t2)){
      ub = t2;
    }else{
      lb = t1;
    }
  }
 
  return lb;
}


int main(){
  int N;
  while(cin >> N){
    vector<Point<double>> ps(N); cin >> ps;

    auto f =
      [&](double x, double y){
        double ret = 0;

        for(auto &p : ps){
          chmax(ret, (p-Point<double>(x,y)).size());
        }

        return ret;
      };

    auto g =
      [&](double x){
        double y = ternary_search_downwards<double>(-1000, 1000, bind(f, x, placeholders::_1));
        return f(x,y);
      };

    auto x = ternary_search_downwards<double>(-1000, 1000, g);
    dump(x);

    auto y = ternary_search_downwards<double>(-1000, 1000, bind(f, x, placeholders::_1));
    dump(y);

    double ans = f(x,y);
    
    cout << ans << endl;
  }
  
  return 0;
}


Measured memory_bytes: 256