#include <bits/stdc++.h>
#define REP(i, n) for(int i = 0;i < n;i++)
#define REPR(i, n) for(int i = n;i >= 0;i--)
#define FOR(i, m, n) for(int i = m;i < n;i++)
#define FORR(i, m, n) for(int i = m;i >= n;i--)
#define SORT(v, n) sort(v, v+n);
#define VSORT(v) sort(v.begin(), v.end());
#define INF 999999999
#define M_PI 3.14159265358979323846
const double eps = 1e-9;

#ifdef __LOCAL
    #define DBG(X) cout << #X << " = " << (X) << endl;
    #define SAY(X) cout << (X) << endl;
#else
    #define DBG(X)
    #define SAY(X)
#endif

#ifdef __LOCAL
    #include <filesystem>
    namespace fs = std::filesystem;
#endif

using namespace std;

using ll = long long int;
using ull = unsigned long long int;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pdd = pair<double, double>;

int dx[]={1, 0, -1, 0, 0};
int dy[]={0, 1, 0, -1, 0};
const int INT_INF = (int)(2e9);
const ll  LL_INF = (ll)(2e18);
const int NIL = -1;
static mt19937 _g(time(nullptr));
 
std::string pad(int num){ char buffer[4]; std::snprintf(buffer, sizeof(buffer), "%03d", num); return buffer;}
inline ll randint(ll a, ll b) { ll w = (_g() << 31LL) ^ _g(); return a + w % (b - a + 1); }
inline void fast_io() { ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr); };
template<typename T> inline T sign(T x) { return T(x > 0) - T(x < 0); }
template<typename T, typename S> inline ostream& operator<<(ostream& os, const pair<T, S> p) { cout << "[" << p.first << ";" << p.second << "]"; return os; }
template<typename T> inline ostream& operator<<(ostream& os, const vector<T>& v) { for (auto el : v) cout << el << " "; return os; }
template<typename T> inline T fetch() { T ret; cin >> ret; return ret; }
template<typename T> inline vector<T> fetch_vec(int sz) { vector<T> ret(sz); for (auto& elem : ret) cin >> elem; return ret; }


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 demplace_backugging
	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.emplace_back(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() {
    fast_io();
    #ifdef __LOCAL
        fs::path p = __FILE__;
        fs::path input,output;
        input = output = p.parent_path();
        input += string("/input/") + string(p.stem()) + string(".txt");
        output += string("/output/") + string(p.stem()) + string(".txt");
        freopen(input.c_str(), "r", stdin);
        freopen(output.c_str(), "w", stdout);
    #endif
	
	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