#include <bits/stdc++.h>

using namespace std;
#define _for(i,j,N) for(int i = (j);i < (N);i++)
#define _rep(i,j,N) for(int i = (j);i <= (N);i++)
#define _dec(i,N,j) for(int i = (N-1);i >= (j);i--)
#define _rec(i,N,j) for(int i = (N);i >=(j);i--)
#define ALL(x) x.begin(),x.end()
#define MEM(a,n) memset(a,n,sizeof(a))
#define fst first
#define scd second
#define PB push_back
#define MP make_pair

typedef long long LL;
typedef long double LD;
typedef pair<int,int> pii;
typedef pair<LL,LL> pll;

int get_int(){int x;scanf("%d",&x);return x;}
LL get_ll(){LL x;scanf("%lld",&x);return x;}
double get_db(){double x;scanf("%lf",&x);return x;}

template<typename T> int chmin(T &a,T b){if(a > b){a = b;return 1;}else return 0;}
template<typename T> int chmax(T &a,T b){if(a < b){a = b;return 1;}else return 0;}
template<typename T>
ostream& operator<<(ostream& os,const vector<T>& v) {_for(i,0,v.size()) os << v[i] << " ";return os;}
template<typename T>
ostream& operator<<(ostream& os,const set<T>& v){for(auto a:v) os << a <<" ";return os;}
template<typename T1,typename T2>
ostream& operator<<(ostream& os,const pair<T1,T2>& v){os << v.fst <<" "<<v.scd << " ";return os;}
template<typename T1,typename T2>
ostream& operator<<(ostream& os,const map<T1,T2>& v){for(auto a:v) cout << a << endl;return os;}

static const int dx[8] = { -1,  0, 1, 0,  1, -1,  1, -1};
static const int dy[8] = {0,  1, 0,  -1,  1, -1, -1,  1};
const double pi  = acos(-1.0);
const double eps = 1e-8;
const LL  INF  = 0x3f3f3f3f3f3f3f3f;
const int inf  = 0x3f3f3f3f;

const int maxn = 60;

struct vec
{
    double x, y;
    vec (const double& x0 = 0, const double& y0 = 0) : x(x0), y(y0) {}
    vec operator + (const vec& t) const {return vec(x+t.x, y+t.y);}
    vec operator - (const vec& t) const {return vec(x-t.x, y-t.y);}
    vec operator * (const double& t) const {return vec(x*t, y*t);}
    vec operator / (const double& t) const {return vec(x/t, y/t);}
    const double len2 () const {return x*x + y*y;}
    const double len () const {return sqrt(len2());}
    vec norm() const {return *this/len();}
    vec rotate_90_c () {return vec(y, -x);}
};

double dot(const vec& a, const vec& b) {return a.x*b.x + a.y*b.y;}
double crs(const vec& a, const vec& b) {return a.x*b.y - a.y*b.x;}

vec lin_lin_int(const vec& p0, const vec& v0, const vec& p1, const vec& v1)
{
    double t = crs(p1-p0, v1) / crs(v0, v1);
    return p0 + v0 * t;
}

vec circle(const vec& a, const vec& b, const vec& c)
{
    return lin_lin_int((a+b)/2, (b-a).rotate_90_c(), (a+c)/2, (c-a).rotate_90_c());
}

int N;
vec plane[maxn];

int main()
{
    scanf("%d", &N);
    _rep(i,1,N) scanf("%lf%lf", &plane[i].x, &plane[i].y);
    random_shuffle(plane+1, plane+N+1);
    vec o;
    double r2 = 0;
    _rep(i,1,N)
    {
        if((plane[i]-o).len2() > r2)
        {
            o = plane[i], r2 = 0;
            _for(j,1,i)
            {
                if((plane[j]-o).len2() > r2)
                {
                    o = (plane[i]+plane[j])/2, r2 = (plane[j]-o).len2();
                    _for(k,1,j)
                    {
                        if((plane[k]-o).len2() > r2)
                        {
                            o = circle(plane[i], plane[j], plane[k]), r2 = (plane[k]-o).len2();
                        }
                    }
                }
            }
        }
    }
    printf("%.10lf\n", sqrt(r2));
    return 0;
}


Measured memory_bytes: 256