#include<bits/stdc++.h>
typedef long long int ll;
typedef unsigned long long int ull;
#define BIG_NUM 2000000000
#define HUGE_NUM 99999999999999999
#define MOD 1000000007
#define EPS 0.000000001
using namespace std;



struct Point{
	Point(double arg_x,double arg_y){
		x = arg_x;
		y = arg_y;
	}

	Point(){
		x = y = 0.0;
	}

	Point operator + (Point p){ return Point(x+p.x,y+p.y); }
	Point operator - (Point p){ return Point(x-p.x,y-p.y);}
	Point operator * (double a){ return Point(a*x,a*y); }
	Point operator / (double a){ return Point(x/a,y/a); }

	double abs(){ return sqrt(norm()); }
	double norm(){ return x*x + y*y; }

	bool operator<(const Point &p) const{
		return x != p.x? x < p.x: y < p.y;
	}

	bool operator == (const Point &p) const{
		return fabs(x-p.x) < EPS && fabs(y-p.y) < EPS;
	}

	double x,y;
};

typedef Point Vector;

struct Line{
	Line(){

	}
	Line(Point a,Point b){
		p[0] = a;
		p[1] = b;
	}
	Point p[2];
};

int N;
Point point[50];


double calc_dist(Point A,Point B){

	return sqrt((A.x-B.x)*(A.x-B.x)+(A.y-B.y)*(A.y-B.y));
}


double calc_slope(Line A){

	if(fabs(A.p[0].x-A.p[1].x) < EPS){

		return DBL_MAX;

	}else if(fabs(A.p[0].y-A.p[1].y) < EPS){

		return 0;

	}else{

		return (A.p[1].y-A.p[0].y)/(A.p[1].x-A.p[0].x);
	}
}

//交点を求める関数
Point calc_Cross_Point(double x1,double x2,double x3,double x4,double y1,double y2,double y3,double y4){
	Point ret;
	ret.x = ((x2-x1)*(y3*(x4-x3)+x3*(y3-y4))-(x4-x3)*(y1*(x2-x1)+x1*(y1-y2)))/((y2-y1)*(x4-x3)-(y4-y3)*(x2-x1));
	if(x1 != x2){
		ret.y = ((y2-y1)*ret.x+y1*(x2-x1)+x1*(y1-y2))/(x2-x1);
	}else{
		ret.y = ((y4-y3)*ret.x+y3*(x4-x3)+x3*(y3-y4))/(x4-x3);
	}
	return ret;
}

//インタフェース関数
Point calc_Cross_Point(Point a,Point b,Point c,Point d){
	return calc_Cross_Point(a.x,b.x,c.x,d.x,a.y,b.y,c.y,d.y);
}

Point calc_minus(Point a,Point b){
    Point ret;

    ret.x = a.x-b.x;
    ret.y = a.y-b.y;

    return ret;
}

int func(double x1,double y1,double x2, double y2, double xp, double yp){
	double naiseki,norm1,norm2,gaiseki;
	norm1 = sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1));
	norm2 = sqrt((xp-x1)*(xp-x1)+(yp-y1)*(yp-y1));
	naiseki = (xp-x1)*(x2-x1)+(yp-y1)*(y2-y1);
	gaiseki = (x2-x1)*(yp-y1)-(xp-x1)*(y2-y1);
	if(gaiseki > EPS){
		return 1;
	}else if(gaiseki < -EPS){
		return -1;
	}
	if(naiseki < -EPS){
		return 2;
	}

	if(norm1 < norm2){
		return -2;
	}
	return 0;
}


bool is_Cross(Line a,Line b){

	if(func(a.p[0].x,a.p[0].y,a.p[1].x,a.p[1].y,b.p[0].x,b.p[0].y)*
			func(a.p[0].x,a.p[0].y,a.p[1].x,a.p[1].y,b.p[1].x,b.p[1].y) <= 0 &&
			func(b.p[0].x,b.p[0].y,b.p[1].x,b.p[1].y,a.p[0].x,a.p[0].y)*
			func(b.p[0].x,b.p[0].y,b.p[1].x,b.p[1].y,a.p[1].x,a.p[1].y) <= 0){
		return true;
	}
	return false;
}

double calc_len(Vector a){
    return sqrt(a.x*a.x+a.y*a.y);
}

double norm(Vector a){
	return a.x*a.x+a.y*a.y;
}

double abs(Vector a){
	return sqrt(norm(a));
}

double cross(Vector a,Vector b){
    return a.x*b.y-a.y*b.x;
}

double dot(Vector a,Vector b){
    return a.x*b.x + a.y*b.y;
}

//線分ではなく直線と点の距離
double getDistanceLP(Line l,Point p){
    return fabs(cross(calc_minus(l.p[1],l.p[0]),calc_minus(p,l.p[0]))/calc_len(calc_minus(l.p[1],l.p[0])));
}

//点と線分の距離
double getDistanceSP(Line l,Point p){
	if(dot(calc_minus(l.p[1],l.p[0]),calc_minus(p,l.p[0])) < 0.0)return calc_len(calc_minus(p,l.p[0]));
	if(dot(calc_minus(l.p[0],l.p[1]),calc_minus(p,l.p[1])) < 0.0)return calc_len(calc_minus(p,l.p[1]));
	return getDistanceLP(l,p);
}

//線分と線分の距離
double getDistance(Line A,Line B){
	if(is_Cross(A,B))return 0.0;
	return min(min(getDistanceSP(A,B.p[0]),getDistanceSP(A,B.p[1])),
			min(getDistanceSP(B,A.p[0]),getDistanceSP(B,A.p[1])));
}

Point calc_Cross_Point(Line A,Line B){

	if(getDistanceSP(B,A.p[0]) < EPS){

		return A.p[0];

	}else if(getDistanceSP(B,A.p[1]) < EPS){

		return A.p[1];

	}else if(getDistanceSP(A,B.p[0]) < EPS){

		return B.p[0];

	}else if(getDistanceSP(A,B.p[1]) < EPS){

		return B.p[1];
	}

	return calc_Cross_Point(A.p[0],A.p[1],B.p[0],B.p[1]);
}


int main(){

	scanf("%d",&N);

	for(int i = 0; i < N; i++){

		scanf("%lf %lf",&point[i].x,&point[i].y);
	}

	Line line1,line2;
	Point center;

	double ans = BIG_NUM;
	double r;
	bool FLG;

	//2点を直径とする場合
	for(int i = 0; i < N-1; i++){
		for(int k = i+1; k < N; k++){

			center = Point((point[i].x+point[k].x)/2,(point[i].y+point[k].y)/2);
			r = calc_dist(center,point[i]);

			FLG = true;

			for(int a = 0; a < N; a++){
				if(a == i || a == k)continue;

				if(calc_dist(center,point[a]) > r){

					FLG = false;
					break;
				}
			}

			if(FLG){

				ans = min(ans,r);
			}
		}
	}

	if(N == 2){

		printf("%.10lf\n",ans);
		return 0;
	}

	double NUM = 20000000;

	//3点を通る場合
	for(int i = 0; i < N-2; i++){
		for(int k = i+1; k < N-1; k++){
			for(int p = k+1; p < N; p++){

				double slope1 = calc_slope(Line(point[i],point[k]));
				double slope2 = calc_slope(Line(point[k],point[p]));

				if(fabs(slope1-slope2) < EPS){ //一直線上

					continue;

				}else{

					Point mid1 = Point((point[i].x+point[k].x)/2,(point[i].y+point[k].y)/2);
					Point mid2 = Point((point[k].x+point[p].x)/2,(point[k].y+point[p].y)/2);

					if(fabs(slope1-DBL_MAX) < EPS){ //垂直

						line1.p[0] = Point(-NUM,mid1.y);
						line1.p[1] = Point(NUM,mid1.y);

					}else if(fabs(slope1) < EPS){ //水平

						line1.p[0] = Point(mid1.x,NUM);
						line1.p[1] = Point(mid1.x,-NUM);

					}else{

						slope1 = (-1.0)/slope1;

						line1.p[0] = Point(mid1.x-NUM,mid1.y-NUM*slope1);
						line1.p[1] = Point(mid1.x+NUM,mid1.y+NUM*slope1);
					}

					if(fabs(slope2-DBL_MAX) < EPS){ //垂直

						line2.p[0] = Point(-NUM,mid2.y);
						line2.p[1] = Point(NUM,mid2.y);

					}else if(fabs(slope2) < EPS){ //水平

						line2.p[0] = Point(mid2.x,NUM);
						line2.p[1] = Point(mid2.x,-NUM);

					}else{

						slope2 = (-1.0)/slope2;

						line2.p[0] = Point(mid2.x-NUM,mid2.y-NUM*slope2);
						line2.p[1] = Point(mid2.x+NUM,mid2.y+NUM*slope2);
					}

					center =  calc_Cross_Point(line1,line2);
				}


				double tmp_dist = calc_dist(center,point[i]);

				bool FLG = true;
				for(int a = 0; a < N; a++){

					if(a == i || a == k || a == p)continue;

					if(calc_dist(center,point[a]) > tmp_dist){

						FLG = false;
						break;
					}
				}

				if(FLG){

					ans = min(ans,tmp_dist);
				}
			}
		}
	}

	printf("%.10lf\n",ans);

	return 0;
}


Measured memory_bytes: 256