#include<bits/stdc++.h>
using namespace std;
//#include<boost/multiprecision/cpp_int.hpp>
//using boost::multiprecision::cpp_int;

#define int long long
#define cint cpp_int
#define endl "\n"
#define REP(i,a,n) for(int i=a;i<n;++i)
#define REPR(i,a,n) for(int i=a;i>n;--i)
#define RUP(a,b) (((a)+(b)-1)/(b))
#define ALL(v) (v).begin(),(v).end()
#define pb push_back
#define mp make_pair
#define mt make_tuple
#define MOD 1000000007
#define INF LLONG_MAX/2
#define PI acos(-1.0)

typedef long long ll;
typedef pair<int,int> Pii;
typedef tuple<int,int,int> Tiii;
typedef vector<int> Vi;
typedef vector<Vi> VVi;
typedef vector<Pii> VPii;
typedef vector<string> Vs;
typedef priority_queue<int> PQi;

template<class T> inline bool chmax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
template<class T> inline bool chmin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
void vout(Vi &v){for(int i=0;i<(v).size();i++) cout<<v[i]<<" ";cout<<endl;}
void vout(Vs &v){for(int i=0;i<(v).size();i++) cout<<v[i]<<" ";cout<<endl;}
void vvout(VVi &v){for(int i=0;i<(v).size();i++) vout(v[i]);}
int gcd(int a,int b){return b?gcd(b,a%b):a;}
int lcm(int a,int b){return a/gcd(a,b)*b;}
int mypow(int x, int n, int m){if(n==0)return 1;if(n%2==0)return mypow(x*x%m,n/2,m);else return x*mypow(x,n-1,m)%m;}
int digit(int k,int i){string s = to_string(k);return s[s.size()-i]-'0';}
void uniq(Vi &v){sort(v.begin(),v.end()); v.erase(unique(v.begin(),v.end()),v.end());} //vectorの同じ要素消す
int ctoi(char c){if(c>='0'&&c<='9'){return c-'0';}return 0;}
int leng(int n){string s=to_string(n); return s.size();} //intの桁数
int digitsum(int n){int ret=0; while(n>0){ret+=n%10;n/=10;}return ret;} //桁和
int lesscount(int x,Vi &a){return lower_bound(a.begin(),a.end(),x)-a.begin();} //vector aにおけるx未満の数の個数
int orlesscount(int x,Vi &a){return upper_bound(a.begin(),a.end(),x)-a.begin();} //vector aにおけるx以下の数の個数
int morecount(int x,Vi &a){return a.size()-orlesscount(x,a);} //vector aにおけるxより大きい数の個数
int ormorecount(int x,Vi &a){return a.size()-lesscount(x,a);} //vector aにおけるx以上の数の個数
int count(int x,Vi &a) {return upper_bound(ALL(a),x)-lower_bound(ALL(a),x);} //vector aにおけるxの個数
Vi accum(Vi &v){Vi ret((v).size()+1);REP(i,0,(v).size()) ret[i+1]=ret[i]+v[i];return ret;}
bool comp(Pii a,Pii b){
    if(a.second != b.second) return a.second<b.second;
    else return a.first<b.first;
}

double inf = numeric_limits<double>::infinity();
pair<double,double> outer(double a,double b,double c,double d,double e,double f) { // 外心
  double x,y;
  y = (e-a)*(a*a+b*b-c*c-d*d)-(c-a)*(a*a+b*b-e*e-f*f);
  y /= 2*(e-a)*(b-d)-2*(c-a)*(b-f);
  if((c-a)!=0){
    x = 2*(b-d)*y-a*a-b*b+c*c+d*d;
    x /= 2*(c-a);
  }
  else {
    x = 2*(b-f)*y-a*a-b*b+e*e+f*f;
    x /= 2*(e-a);
  }
  
  if(x==inf||x==-inf||y==inf||y==-inf) return mp(INF,INF); // (INF,INF)のときは存在しない
  return mp(x,y);
}

bool check(double nx,double ny,double r,vector<double> &x,vector<double> &y){
    int n=x.size();
    bool ret=true;
    REP(i,0,n){
        if((x[i]-nx)*(x[i]-nx)+(y[i]-ny)*(y[i]-ny) > r) ret=false;
    }
    return ret;
}

double dist(double x1,double y1,double x2,double y2){
    return (x1-x2)*(x1-x2)+(y1-y2)*(y1-y2);
}

signed main(){cin.tie(0);cout.tie(0);ios::sync_with_stdio(false);cout<<fixed<<setprecision(15);
    int n;
    cin>>n;
    vector<double> x(n),y(n);
    REP(i,0,n) cin>>x[i]>>y[i];

    double ans=DBL_MAX;
    REP(i,0,n){
        REP(j,i+1,n){
            double nx=(x[i]+x[j])/2;
            double ny=(y[i]+y[j])/2;
            double nr=max(dist(x[i],y[i],nx,ny),dist(x[j],y[j],nx,ny));
            if(check(nx,ny,nr,x,y)) chmin(ans,nr);
        }
    }
    REP(i,0,n){
        REP(j,i+1,n){
            REP(k,j+1,n){
                pair<double,double> outerp=outer(x[i],y[i],x[j],y[j],x[k],y[k]);
                double nx=outerp.first;
                double ny=outerp.second;
                double nr=max({dist(x[i],y[i],nx,ny),dist(x[j],y[j],nx,ny),dist(x[k],y[k],nx,ny)});
                if(check(nx,ny,nr,x,y)) chmin(ans,nr);
            }
        }
    }

    cout<<sqrt(ans)<<endl;
    return 0;
}


Measured memory_bytes: 256