#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define nl '\n'
const int N = 1e5+5;

double a[N], b[N];

double dis(double x, double y, double xx, double yy){
    return ((x-xx)*(x-xx)+(y-yy)*(y-yy));
}

int main() {
    int n; cin >> n;
    double mxx = -2e9, mxy = -2e9;
    double mnx = 2e9, mny = 2e9;
    for(int i=0;i<n;++i) cin >> a[i] >> b[i];
    for(int i=0;i<n;++i) mxx = max(mxx, a[i]), mnx = min(mnx, a[i]);
    for(int i=0;i<n;++i) mxy = max(mxy, b[i]), mny = min(mny, b[i]);
    double mx = (mxx + mnx) / 2.0;
    double my = (mxy + mny) / 2.0;
    // cerr << mx << endl;
    // cerr << my << endl;

    double l = 0;
    double r = 1e6;
    int t = 100;
    while(t--){
        double mid = (l+r)/2.0;
        bool ok = true;
        for(int i=0;i<n;++i) ok &= (dis(a[i], b[i], mx, my) <= mid*mid);
        if(ok) r = mid;
        else l = mid;
    }
    cout << fixed << setprecision(10) << l << nl;

}