#include "bits/stdc++.h"
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;

typedef long long ll;

const ll MOD = 1e9 + 7;

int main() {
    int N;
    cin >> N;
    vector<double> x(N), y(N);
    rep(i, N) cin >> x[i] >> y[i];
    double lx = 0, hx = 1000, ans = 2e6;
    rep(i, 500) {
        double mx[2] = {(lx * 2 + hx) / 3, (lx + hx * 2) / 3}, dx[2] = {2e6, 2e6};
        rep(j, 2) {
            double ly = 0, hy = 1000;
            rep(k, 500) {
                double my[2] = {(ly * 2 + hy) / 3, (ly + hy * 2) / 3}, dy[2] = {0, 0};
                rep(l, 2) {
                    rep(m, N) {
                        dy[l] = max(dy[l], (mx[j] - x[m]) * (mx[j] - x[m]) + (my[l] - y[m]) * (my[l] - y[m]));
                    }
                    dx[j] = min(dx[j], dy[l]);
                }
                if (dy[0] < dy[1]) hy = my[1];
                else ly = my[0];
            }
            ans = min(ans, dx[j]);
        }
        if (dx[0] < dx[1]) hx = mx[1];
        else lx = mx[0];
    }
    cout << setprecision(20) << sqrt(ans) << endl;
}