#include<bits/stdc++.h>
using namespace std;using ll=long long;using vi=vector<int>;using vvi=vector<vi>;using vl=vector<ll>;using vvl=vector<vl>;using P=pair<int,int>;using PL=pair<ll,ll>;using vp=vector<P>;using vpl=vector<PL>;
#define pqueue priority_queue
//template<typename T>constexpr auto inf=numeric_limits<T>::max()/2;constexpr int INF=inf<int>,MOD=1000000007;constexpr ll LINF=inf<ll>;
#define _ol3(_1,_2,_3,name,...)name
#define _rep(i,n)_repi(i,0,n)
#define _repi(i,a,b)for(int i=a,i##_l=(b);i<i##_l;++i)
#define REP(...)_ol3(__VA_ARGS__,_repi,_rep,)(__VA_ARGS__)
#define REPR(i,n)for(int i=n-1;i>=0;--i)
#define REPA(i,v)REP(i,(v).size())
#define all(v)(v).begin(),(v).end()
#define rall(v)(v).rbegin(),(v).rend()
#define bit(n)(1ll<<(n))
#define F first
#define S second
#define endl '\n'
#define cho(n,a,b)cout<<((n)?a:b)<<endl
void YES(int n){cho(n,"YES","NO");}void Yes(int n){cho(n,"Yes","No");}void Poss(int n){cho(n,"Possible","Impossible");}
void _print(ostream&){}template<class T,class...U>void _print(ostream&s,const T&t,const U&...u){s<<t<<(sizeof...(u)?' ':'\n');_print(s,u...);}
template<class...T>void print(const T&...t){_print(cout,t...);}template<class...T>void dprint(const T&...t){_print(cerr,t...);}
#ifndef LOCAL
struct osd{template<class T>osd&operator<<(const T&t){return*this;}};osd cer_;
#define dprint(...)
#define cerr cer_
#endif
#define dbg(x) dprint("@l",__LINE__,':',#x,'=',x)
template<class T>bool chmax(T&a,const T&b){bool x=a<b;x?a=b:b;return x;}template<class T>bool chmin(T&a,const T&b){bool x=a>b;x?a=b:b;return x;}
template<class T,class U>ostream&operator<<(ostream&o,const pair<T,U>&p){return o<<p.F<<' '<<p.S;}
template<class T,class U>istream&operator>>(istream&i,pair<T,U>&p){return i>>p.F>>p.S;}
template<class T>class iterable{static false_type c(string v);template<class U>static auto c(U v)->decltype(all(v),true_type());static false_type c(...);public:const static bool value=decltype(c(declval<T>()))::value;};
template<class T,enable_if_t<iterable<T>::value,int> =0>ostream&operator<<(ostream&o,const T&v){for(auto&&i:v)o<<i<<' ';return o;}
template<class T>istream&operator>>(istream&i,vector<T>&v){for(T&j:v)i>>j;return i;}template<class T>vector<T>&operator<<(vector<T>&v,const T&t){v.push_back(t);return v;}
template<class T,class U>queue<T,U>&operator<<(queue<T,U>&v, const T&t){v.push(t);return v;}template<class T,class U>queue<T,U>&operator>>(queue<T,U>&v, T&t){t=v.front();v.pop();return v;}
template<class T,class U,class V>pqueue<T,U,V>&operator<<(pqueue<T,U,V>&v, const T&t){v.push(t);return v;}template<class T,class U,class V>pqueue<T,U,V>&operator>>(pqueue<T,U,V>&v, T&t){t=v.front();v.pop();return v;}
template<class T,class U>stack<T,U>&operator<<(stack<T,U>&v, const T&t){v.push(t);return v;}template<class T,class U>stack<T,U>&operator>>(stack<T,U>&v, T&t){t=v.front();v.pop();return v;}
template<class T,class U,class V>set<T,U,V>&operator<<(set<T,U,V>&v,const T&t){v.insert(t);return v;}template<class T,class U,class V>multiset<T,U,V>&operator<<(multiset<T,U,V>&v,const T&t){v.insert(t);return v;}
template<class T,enable_if_t<is_integral<T>::value,int> =0>T mod(T a, T b){if(a>0)return a%b;return b-(-a%b);}
template<class T,enable_if_t<is_floating_point<T>::value,int> =0>T mod(T a, T b){if(a>0)return fmod(a,b);return b-fmod(-a,b);}
template<class T,class U>pair<T,U>&operator+=(pair<T,U>&a, pair<T,U>&b){a.F+=b.F;a.S+=b.S;return a;}template<class T,class U>pair<T,U>operator+(const pair<T,U>&a, const pair<T,U>&b){T r=a;return r+=b;}
template<class T,class U>pair<T,U>&operator-=(pair<T,U>&a, pair<T,U>&b){a.F-=b.F;a.S-=b.S;return a;}template<class T,class U>pair<T,U>operator-(const pair<T,U>&a, const pair<T,U>&b){T r=a;return r-=b;}
template<class T,class U>pair<T,U>operator-(pair<T,U>&a){return mp(-a.F, -a.S);}

using ld = double;
using PC = complex<ld>;
using G = vector<PC>;
const ld pi = acos(-1);
const ld eps = 1e-10;
//const ld inf = 1e12;

ld cross(const PC& a, const PC& b) { return a.real()*b.imag() - a.imag()*b.real(); }
ld dot(const PC& a, const PC& b) { return a.real()*b.real() + a.imag()*b.imag(); }

using C = pair<ld, PC>;
#define rad first
#define pnt second

C smallest_enclosing_disc(vector<PC> ps){
    auto c3 = [](const PC &a, const PC &b, const PC &c){
        ld A = norm(b - c);
        ld B = norm(c - a);
        ld C = norm(a - b);
        ld S = abs(cross(b - a, c - a));
        PC p = (A*(B+C-A)*a + B*(C+A-B)*b + C*(A+B-C)*c) / (4*S*S);
        ld r = abs(p - a);
        return make_pair(r, p);
    };

    auto c2 = [](const PC &a, const PC &b){
        PC c = (a + b) / (ld)2;
        ld r = abs(a - c);
        return make_pair(r, c);
    };

    auto in_circle = [](const PC &a, const C &c){
        return norm(a - c.pnt) <= c.rad*c.rad + eps;
    };

    int n = ps.size();
    random_shuffle(ps.begin(), ps.end());
    C c = c2(ps[0], ps[1]);
    for(int i = 2; i < n; ++i){
        if(!in_circle(ps[i], c)){
            c = c2(ps[0], ps[i]);
            for(int j = 1; j < i; ++j){
                if(!in_circle(ps[j], c)){
                    c = c2(ps[j], ps[i]);
                    for(int k = 0; k < j; ++k){
                        if(!in_circle(ps[k], c)){
                            c = c3(ps[i], ps[j], ps[k]);
                        }
                    }
                }
            }
        }
    }
    return c;
}
int main(){
    cin.tie(0);ios::sync_with_stdio(0);
    cout<<setprecision(10);
    int n;
    cin>>n;
    vp p(n);
    cin>>p;
    vector<PC> ppc(n);
    REP(i,n)ppc[i]=PC(p[i].F, p[i].S);

    PC c;long double r;
    tie(r,c)=smallest_enclosing_disc(ppc);
    printf("%0.18f",(double)r);
}


Measured memory_bytes: 256