#include<bits/stdc++.h>
#define FileIO          freopen("input.in", "r", stdin); freopen("output.in", "w", stdout)
#define ll              long long
#define input_vec(v)    for(int II=0; II<v.size(); II++) cin >> v[II];
#define sortf(v)        sort(v.begin(), v.end());
#define sortr(v)        sort(v.rbegin(), v.rend());
#define print_vec(v)    for(int II=0; II<v.size(); II++){cout << v[II];} cout << endl;

using namespace std;
long double sqr(long double n){return n*n;}
long double dist(pair <long double, long double> a, pair <long double, long double> b){
    return sqrtl(sqr(a.first-b.first)+sqr(a.second-b.second));
}
void test_case(int tc)
{
    
}

int main()
{
    
//    if(fopen("input.in", "r")) FileIO;
    int n;
    cin>>n;
    vector <pair<long double, long double>> v(n);
    for(int i=0;i<n;i++){
        long double a, b;
        cin>>a>>b;
        v[i]=make_pair(a, b);
    }
    // for(auto i: v){
    //     cout<<i.first<<" "<<i.second<<endl;
    // }
    long double DIST=-1;
    for(int i=0;i<n;i++){
        for(int j=i;j<n;j++){
            DIST=max(dist(v[i], v[j]), DIST);
        }
    }

    cout<<fixed<<setprecision(18)<<DIST/2<<endl;
}