#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];
    ll d = -1.0;
    set<pair<int, int>> st;
    for(int i=0;i<n;++i) st.insert({a[i], b[i]});
    if(st.size() == 1) {
        cout << "0.000001\n";
        return 0;
    }
    for(int i=0;i<n;++i){
        for(int j=0;j<n;++j){
            d = max(d, dis(a[i], b[i], a[j], b[j]));
            // cerr << d << endl;
        }
    }
    cout << fixed << setprecision(10) << sqrtl(d) / 2 << nl;
}