#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("unroll-loops")
#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
#include<queue>
#include<map>
#include<math.h>
#include<iomanip>
#include<set>
#include<numeric>
#include<cstring>
#include<cstdio>
#include<functional>
#include<bitset>
#include<limits.h>
#include<cassert>
#include<iterator>
#include<complex>
#include<stack>
#include<unordered_map>
#include<unordered_set>
#include<time.h>
#include<random>

using namespace std;

#define REP(i, n) for(int i = 0;i < n;++i)
#define REPR(i, n) for(int i = n-1;i >= 0;--i)
#define FOR(i, m, n) for(int i = m;i < n;++i)
#define FORR(i, m, n) for(int i = m-1;i >= n;--i)
#define SORT(v, n) sort(v, v+n);
#define VSORT(v) sort(v.begin(), v.end());
#define REVERSE(v,n) reverse(v,v+n);
#define VREVERSE(v) reverse(v.begin(), v.end())
#define ll long long
#define pb(a) push_back
#define print(x) cout<<(x)<<endl
#define pe(x) cout<<(x)<<" "
#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define lb(v,n) lower_bound(v.begin(), v.end(), n)
#define ub(v,n) upper_bound(v.begin(), v.end(), n)
#define int long long
#define all(x) (x).begin(), (x).end()
#define print_space(v) REP(i,v.size())cout << v[i] << ((i == v.size() - 1) ? "\n" : " ")
template<typename T1, typename T2> inline void chmin(T1 & a, T2 b) { if (a > b) a = b; }
template<typename T1, typename T2> inline void chmax(T1& a, T2 b) { if (a < b) a = b; }
typedef pair<double, double>P;
const int MOD = 1e9 + 7; const int MAX = 200020;
const double pi = acos(-1); const double EPS = 1e-12;
const ll INF = 2e18;


double dist(double x1, double x2, double y1, double y2) {
	return sqrt((x1 - x2)*(x1 - x2) + (y1 - y2)*(y1 - y2));
}
double dist(P &p1, P &p2) {
	double x1 = p1.first, x2 = p2.first, y1 = p1.second, y2 = p2.second;
	return sqrt((x1 - x2)*(x1 - x2) + (y1 - y2)*(y1 - y2));
}
vector<P>ps;
P cen(vector<P> &vec) {
	vector<double>x(3);
	vector<double>y(3);
	REP(i, 3) {
		x[i] = vec[i].first;
		y[i] = vec[i].second;
	}
	double X = 0, Y = 0;
	vector<double> line(3);
	double sum = 0;
	REP(i, 3) {
		line[i] = dist(vec[(i + 1) % 3], vec[(i + 2) % 3]);
		sum += line[i] * line[i];
		line[i] = line[i] * line[i];
	}
	double div = 0;
	REP(i, 3) {
		div += (sum - 2 * line[i])*line[i];
	}
	REP(i, 3) {
		X += x[i] * (sum - 2 * line[i])*line[i] / div;
		Y += y[i] * (sum - 2 * line[i])*line[i] / div;
	}
	return make_pair(X, Y);
}
double ra(vector<P>&vec) {
	vector<double> line(3);
	double sum = 0;
	REP(i, 3) {
		line[i] = dist(vec[(i + 1) % 3], vec[(i + 2) % 3]);
		sum += line[i];
	}
	double div = sum;
	REP(i, 3) {
		div *= (sum - 2 * line[i]);

	}
	if (div <= 0)return 0;
	div = sqrt(div);
	return line[0] * line[1] * line[2] / div;
}
void solve() {
	double mx = 0;

	int N; cin >> N;
	srand(time(NULL));
	vector<double>X(N), Y(N);
	REP(i, N)cin >> X[i] >> Y[i];
	REP(i, N) {
		ps.push_back({ X[i],Y[i] });
	}


	const double d = 1e-10;
	double ans = 1e9;
	const int SPLIT = 1000;
	clock_t start = clock();
	double sx = 0, sy = 0;
	double l = 1000;
	P p = { sx,sy };
	REP(__, 100000) {
		double mx = 0;
		P nxt = { 0,0 };
		REP(i, N) {
			double res = dist(p, ps[i]);
			if (res > mx) {
				mx = res;
				nxt = ps[i];
			}
		}
		double theta = atan2(nxt.second - p.second, nxt.first - p.first);
		p.first = p.first + l * cos(theta);
		p.second = p.second + l * sin(theta);
		if (abs(ans - mx) < 1e-10)break;
		ans = min(ans, mx);
		l *= 0.99;
		clock_t end = clock();
		const double time = static_cast<double>(end - start) / CLOCKS_PER_SEC * 1000.0;
		if (time > 1000)break;
	}

	cout << setprecision(10) << ans << endl;
}

signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	//int q;cin>>q;
	//while(q--)
	solve();
}




Measured memory_bytes: 640