#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef pair<ll,ll> pll;
typedef vector<bool> vb;
const ll oo = 0x3f3f3f3f3f3f3f3f;
const double eps = 1e-9;
#define sz(c) ll((c).size())
#define all(c) begin(c), end(c)
#define FOR(i,a,b) for (ll i = (a); i < (b); i++)
#define FORD(i,a,b) for (ll i = (b)-1; i >= (a); i--)
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define eb emplace_back
#define xx first
#define yy second
#define has(c,i) ((c).find(i) != end(c))
#define TR(X) ({ if(1) cerr << "TR: " << (#X) << " = " << (X) << endl; })


struct point { double x, y; };

point  operator+(point a,  point b) { return {a.x+b.x, a.y+b.y}; }
point  operator-(point a,  point b) { return {a.x-b.x, a.y-b.y}; }
point  operator*(double t, point b) { return {t*b.x, t*b.y}; }
point  operator/(point a, double t) { return {a.x/t, a.y/t}; }

double operator*(point a,  point b) { return a.x*b.x + a.y*b.y; } // dot product
double operator%(point a,  point b) { return a.x*b.y - a.y*b.x; } // cross product

bool operator<(point a, point b) { // lexicographical compare
	if (abs(a.x-b.x) > eps) return a.x < b.x;
	return a.y + eps < b.y;
}

ostream &operator<<(ostream &out, point a) { // for debugging
	return out << "(" << a.x << "," << a.y << ")";
}

double abs(point a) { return hypot(a.x,a.y); }
point perp(point a) { return {-a.y,a.x}; } // rotate 90 degrees counterclockwise
point normalize(point a) { return a/abs(a); }

double angle(point a, point b) { // angle between two vectors (0 to pi)
	double d = normalize(a)*normalize(b);
	return acos(max(-1.0,min(1.0,d)));
}

ll ccw(point a, point b, point c) { // returns 1|0|-1 if c is left|straight|right of ab
	double res = (b-a)%(c-a);
	return abs(res) > eps ? (res > 0 ? 1 : -1) : 0;
}

bool on_segment(point p, point a, point b) {
	return (a-p)*(b-p) < eps && ccw(a,b,p) == 0;
}

// point that has equal distance to a,b,c
point circumcenter(point a, point b, point c) {
	b = b-a, c = c-a;
	return a + perp(c*c*b - b*b*c)/(b%c)/2;
}

// center of incircle of triangle a,b,c
point incenter(point a, point b, point c) {
	double u = abs(b-c), v = abs(c-a), w = abs(a-b);
	return (u*a + v*b + w*c) / (u + v + w);
}

// finds all lines tangent to two circles (p,r) and (q,s)
// first outer, then inner tangents; be careful with touching/intersecting circles!
void find_tangents(point p, double r, point q, double s, vector<pair<point,point>> &res) {
	FOR(inner,0,2) {
		point v = q-p;
		double h = sqrt(v*v - (r-s)*(r-s));
		for (ll sign: {-1,1}) {
			point n = normalize((r-s)*v + sign*h*perp(v));
			res.eb(p+r*n, q+s*n);
		}
		s = -s;
	}
}

double needed_radius(vector<point> &a, point p) {
	double res = 0;
	for (point q: a) res = max(res, abs(p-q));
	return res;
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	ll n; cin >> n;
	vector<point> a(n);
	FOR(i,0,n) cin >> a[i].x >> a[i].y;
	
	point best_center = {0,0};
	double best_radius = 2e9;
	
	auto relax = [&](point center) {
		double radius = needed_radius(a,center);
		if (radius < best_radius) best_center = center, best_radius = radius;
	};

	FOR(i,0,n) FOR(j,i+1,n) FOR(k,j+1,n) relax(circumcenter(a[i],a[j],a[k]));
	FOR(i,0,n) FOR(j,i+1,n) relax((a[i]+a[j])/2);
	FOR(i,0,n) relax(a[i]);
	
	cout << fixed << setprecision(20) << best_radius << endl;
}



Measured memory_bytes: 256