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

ll a[N], b[N];

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

int main() {
    int n; cin >> n;
    for(int i=0;i<n;++i) cin >> a[i] >> b[i];
    long double d = 0;
    for(int i=0;i<n;++i){
        for(int j=0;j<n;++j){
            d = max(d, (long double) dis(a[i], b[i], a[j], b[j]));
            // cerr << d << endl;
        }
    }
    cout << fixed << setprecision(10) << sqrt(d) / 2.0<< nl;
}