#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)
#define fore(i,a) for(auto &i:a)
#define all(x) (x).begin(),(x).end()
#pragma GCC optimize ("-O3")
using namespace std; void _main(); int main() { cin.tie(0); ios::sync_with_stdio(false); _main(); }
typedef long long ll; const int inf = INT_MAX / 2; const ll infl = 1LL << 60;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a = b; return 1; } return 0; }
//---------------------------------------------------------------------------------------------------
const double EPS = 1e-8, INF = 1e12, PI = 2 * acos(0.0);
typedef complex<double> P;
namespace std {
	bool operator < (const P& a, const P& b) { return real(a) != real(b) ? real(a) < real(b) : imag(a) < imag(b); }
	bool operator == (const P& a, const P& b) { return abs(real(a) - real(b)) < EPS && abs(imag(a) - imag(b)) < EPS; }
	P operator / (const P& a, const double& b) { return P(real(a) / b, imag(a) / b); }
	P operator * (const P& a, const double& b) { return P(real(a) * b, imag(a) * b); }
}
double cross(const P& a, const P& b) { return imag(conj(a)*b); }
double dot(const P& a, const P& b) { return real(conj(a)*b); }
struct L : public vector<P> { L() {} L(const P &a, const P &b) { push_back(a); push_back(b); } };
typedef vector<P> G;
struct C { P p; double r; C() {} C(const P &p, double r) : p(p), r(r) {} };
int ccw(P a, P b, P c) {
	b -= a; c -= a;
	if (cross(b, c) > 0)   return 0;       // counter clockwise
	if (cross(b, c) < 0)   return 1;       // clockwise
	if (dot(b, c) < 0)     return +2;       // c--a--b on line
	if (norm(b) < norm(c)) return -2;       // a--b--c on line
	return 0;
}
P rotate(P vec, double ang) {
	double x = real(vec), y = imag(vec);
	return P(x * cos(ang) - y * sin(ang), x * sin(ang) + y * cos(ang));
}
bool intersectLL(const L &l, const L &m) {
	return abs(cross(l[1] - l[0], m[1] - m[0])) > EPS || // non-parallel
		   abs(cross(l[1] - l[0], m[0] - l[0])) < EPS;   // same line
}
bool intersectLS(const L &l, const L &s) {
	return cross(l[1] - l[0], s[0] - l[0])*       // s[0] is left of l
		   cross(l[1] - l[0], s[1] - l[0]) < EPS; // s[1] is right of l
}
bool intersectLP(const L &l, const P &p) {
	return abs(cross(l[1] - p, l[0] - p)) < EPS;
}
bool intersectSS(const L &s, const L &t) {
	return ccw(s[0], s[1], t[0])*ccw(s[0], s[1], t[1]) <= 0 &&
		   ccw(t[0], t[1], s[0])*ccw(t[0], t[1], s[1]) <= 0;
}
bool intersectSP(const L &s, const P &p) {
	return abs(s[0] - p) + abs(s[1] - p) - abs(s[1] - s[0]) < EPS; // triangle inequality
}
bool intersectSSwithoutPoint(const L &s, const L &t) { // not verified
	return ccw(s[0], s[1], t[0])*ccw(s[0], s[1], t[1]) < 0 &&
		   ccw(t[0], t[1], s[0])*ccw(t[0], t[1], s[1]) < 0;
}
P crosspoint(const L &l, const L &m) {
	double A = cross(l[1] - l[0], m[1] - m[0]);
	double B = cross(l[1] - l[0], l[1] - m[0]);
	if (abs(A) < EPS && abs(B) < EPS) return m[0]; // same line
	if (abs(A) < EPS) assert(false); // !!!PRECONDITION NOT SATISFIED!!!
	return m[0] + B / A * (m[1] - m[0]);
}
double argument(const P &a, const P &b) { // argument for A->B[-PI,PI]
	double ax = real(a), ay = imag(a), bx = real(b), by = imag(b);
	return atan2(by - ay, bx - ax);
}
// A->B->C時計回りの時の外角
// argument for A->B->C
double threePointArgumentTokei(const P &a, const P &b, const P &c) {
	P ba = b - a;
	P cb = c - b;

	double r1 = atan2(real(ba), imag(ba)) - PI / 2.0;
	while (r1<-PI) r1 += 2 * PI;
	while (PI<r1) r1 -= 2 * PI;
	double r2 = atan2(real(cb), imag(cb)) - PI / 2.0;
	while (r2<-PI) r2 += 2 * PI;
	while (PI<r2) r2 -= 2 * PI;

	//cout << id << "\t" << r1 << "\t" << r2 << endl;

	double range = 0;
	if (r1 >= 0 && r2>0) range = r2 - r1;
	else if (r1<0 && r2 >= 0) range = -r1 + r2;
	else if (r1 >= 0 && r2<0) range = (PI - r1) + (PI + r2);
	else range = r2 - r1;

	return range;
}
// A-B-Cの成す各のうち小さい方
double threePointArgument(const P &a, const P &b, const P &c) {
	double x = argument(b, a);
	double y = argument(b, c);

	double res = x - y;
	while (res < 0) res += PI * 2;
	while (PI * 2 <= res) res -= PI * 2;

	return min(res, 2 * PI - res);
}
// 三点より中心導出
P three_point_circle(const P& a, const P& b, const P& c) {
	P x = 1.0 / conj(b - a), y = 1.0 / conj(c - a);
	return (y - x) / (conj(x)*y - x * conj(y)) + a;
}
/*---------------------------------------------------------------------------------------------------
　　　　　　　　　　　 ∧＿∧
　　　　　 ∧＿∧ 　（´<_｀ ）　 Welcome to My Coding Space!
　　　　 （ ´_ゝ`）　/　 ⌒i
　　　　／　　　＼　 　  |　|
　　　 /　　 /￣￣￣￣/　　|
　 ＿_(__ﾆつ/　    ＿/ .| .|＿＿＿＿
　 　　　＼/＿＿＿＿/　（u　⊃
---------------------------------------------------------------------------------------------------*/






int N;
P xy[55];
//---------------------------------------------------------------------------------------------------
using ld = double;
double smallestEnclosingCircle(vector<P> &v) {
	if (v.size() <= 1) return 0;

	auto c3 = [](const P &a, const P &b, const P &c) {
		ld A = norm(b - c);
		ld B = norm(c - a);
		ld Co = norm(a - b);
		ld S = abs(cross(b - a, c - a));
		P p = (A*(B + Co - A)*a + B * (Co + A - B)*b + Co * (A + B - Co)*c) / (4 * S*S);
		ld r = abs(p - a);
		return C(p, r);
	};

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

	auto in_circle = [](const P &a, const C &c) {
		return norm(a - c.p) <= c.r *c.r + EPS;
	};

	int n = v.size();
	random_shuffle(v.begin(), v.end());
	C c = c2(v[0], v[1]);
	for (int i = 2; i < n; ++i) {
		if (!in_circle(v[i], c)) {
			c = c2(v[0], v[i]);
			for (int j = 1; j < i; ++j) {
				if (!in_circle(v[j], c)) {
					c = c2(v[j], v[i]);
					for (int k = 0; k < j; ++k) {
						if (!in_circle(v[k], c)) {
							c = c3(v[i], v[j], v[k]);
						}
					}
				}
			}
		}
	}
	return c.r;
}
//---------------------------------------------------------------------------------------------------
void _main() {
	cin >> N;
	vector<P> v;
	rep(i, 0, N) {
		double x, y;
		cin >> x >> y;
		xy[i] = P(x, y);
		v.push_back(xy[i]);
	}

	printf("%.8f\n", smallestEnclosingCircle(v));
}


Measured memory_bytes: 256