#include <bits/stdc++.h>
#ifdef LOCAL_DEBUG
#define DEBUG 1
#define CERR if(DEBUG) cerr
#define MACRO(_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,NAME,...) NAME
#define pr(...) CERR<<MACRO(__VA_ARGS__,pr10,pr9,pr8,pr7,pr6,pr5,pr4,pr3,pr2,pr1)(__VA_ARGS__)<<endl
#define pr1(a) (#a)<<"="<<(a)<<" "
#define pr2(a,b) pr1(a)<<pr1(b)
#define pr3(a,b,c) pr1(a)<<pr2(b,c)
#define pr4(a,b,c,d) pr1(a)<<pr3(b,c,d)
#define pr5(a,b,c,d,e) pr1(a)<<pr4(b,c,d,e)
#define pr6(a,b,c,d,e,f) pr1(a)<<pr5(b,c,d,e,f)
#define pr7(a,b,c,d,e,f,g) pr1(a)<<pr6(b,c,d,e,f,g)
#define pr8(a,b,c,d,e,f,g,h) pr1(a)<<pr7(b,c,d,e,f,g,h)
#define pr9(a,b,c,d,e,f,g,h,i) pr1(a)<<pr8(b,c,d,e,f,g,h,i)
#define pr10(a,b,c,d,e,f,g,h,i,j) pr1(a)<<pr9(b,c,d,e,f,g,h,i,j)
#define prArr(a){CERR<<(#a)<<"={";int i=0;for(auto t:(a))CERR<<(i++?", ":"")<<t;CERR<<"}"<<endl;}
#else
#define DEBUG 0
#define pr(...)
#define prArr(a)
#endif
using namespace std;
using Int = long long;
using _int = int;
using ll = long long;
using Double = long double;
const Int INF = (1LL<<60)+1e9; // ~ 1.15 * 1e18
const Int mod = (1e9)+7;

const Double PI = 6.0 * asin((Double)0.5);
//using P = pair<Int,Int>;
template<class T> T Max(T &a,T b){return a=max(a,b);}
template<class T> T Min(T &a,T b){return a=min(a,b);}
template<class T1, class T2> ostream& operator<<(ostream& o,pair<T1,T2> p){return o<<"("<<p.first<<","<<p.second<<")";}
template<class T1, class T2, class T3> ostream& operator<<(ostream& o,tuple<T1,T2,T3> t){return o<<"("<<get<0>(t)<<","<<get<1>(t)<<","<<get<2>(t)<<")";}
template<class T1, class T2> istream& operator>>(istream& i,pair<T1,T2> &p){return i>>p.first>>p.second;}
template<class T> ostream& operator<<(ostream& o,vector<T> a){Int i=0;for(T t:a)o<<(i++?" ":"")<<t;return o;}
template<class T> istream& operator>>(istream& i,vector<T> &a){for(T &t:a)i>>t;return i;}
//INSERT ABOVE HERE
const Double EPS = 1e-12;
typedef complex<Double> P;
typedef pair<P,P> L;
Double dot(P a, P b){ return real(conj(a)*b); }
Double cross(P a, P b){ return imag(conj(a)*b); }

// ２直線間の交点
P crossPoint(L l, L m){
  Double A = cross(l.second - l.first, m.second - m.first);
  Double B = cross(l.second - l.first, l.second - m.first);
  if(fabs(A) < EPS && fabs(B) < EPS) return m.first;
  else if(fabs(A) >= EPS) return m.first + B / A * (m.second - m.first);
  assert(0);
  return P();
}

Int n;
vector<Double> X, Y;
Double calc(){
  auto isTri=[](P a, P b, P c){
    vector<Double> d{abs(a-b),abs(b-c),abs(c-a)};
    sort(d.begin(),d.end());
    return d[0] + d[1] > d[2]+EPS;
  };

  auto rot=[](L a,P b){
    b /= abs(b);
    auto s = a.first;
    auto t = a.second;
    return L(s, (t-s)*b+s);
  };

  auto getC=[&](P a,P b,P c){
    P e = P(0,1);
    L ab = L((a-b)*P(0.5,0)+b,a);
    L ac = L((a-c)*P(0.5,0)+c,a);
    ab = rot(ab, e);
    ac = rot(ac, e);
    return crossPoint(ab, ac);
  };

  auto getBit=[&](P a, Double r){
    Int bit = 0;
    for(Int i=0;i<n;i++) if(abs(a - P(X[i],Y[i])) <= r + EPS) bit += 1;
    return bit;
  };

  Double res = INF;

  for(Int i=0;i<n;i++)
    for(Int j=0;j<n;j++){
      P a = P(X[i], Y[i]);
      P b = P(X[j], Y[j]);
      P cp = (b - a) * P(0.5, 0) + a;
      Double r = abs(cp - a);
      Int bit = getBit(cp,r);
      if(bit == n) Min(res, r);
    }

  for(Int i=0;i<n;i++)
    for(Int j=i+1;j<n;j++)
      for(Int k=j+1;k<n;k++){
        P a = P(X[i], Y[i]);
        P b = P(X[j], Y[j]);
        P c = P(X[k], Y[k]);
        if(!isTri(a, b, c)) continue;
        P cp = getC(a, b, c);
        Double r = abs(cp - a);
        Int bit = getBit(cp,r);
        if(bit == n) Min(res, r);
        assert(abs(abs(cp-a)-abs(cp-b))<EPS && abs(abs(cp-a)-abs(cp-c))<EPS);
        //assert((bit>>i&1)&&(bit>>j&1)&&(bit>>k&1));
      }
  return res;
}


signed main(){
  srand((unsigned)time(NULL));
  cin.tie(0);
  ios_base::sync_with_stdio(0);
  cout << fixed << setprecision(12);

  cin>>n;
  X.resize(n);
  Y.resize(n);
  for(Int i=0;i<n;i++) cin>>X[i]>>Y[i];
  Double ans= calc();
  cout<<ans<<endl;
  return 0;
}


Measured memory_bytes: 384