/* SRIJON
        SINGHA
            SAMANTA */
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef long double ld;
#define nl "\n"
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define yes cout << "YES" << nl
#define no cout << "NO" << nl
#define fi first
#define sec second
#define pb push_back
#define ppb pop_back
#define pf push_front
#define ppf pop_front
#define FIO                           \
    ios_base::sync_with_stdio(false); \
    cin.tie(NULL);                    \
    cout.tie(NULL);
const int mod = 1e9 + 7;

struct cor{
    ll x,y;
};

int32_t main()
{
    FIO

    ll n;   cin>>n;
    vector<cor>v(n);
    for(ll i=0;i<n;i++) cin>>v[i].x>>v[i].y;
    ll mx=LLONG_MIN;
    for(ll i=0;i<n;i++)
    {
        for(ll j=0;j<n;j++)
        {
            ll dis=(v[i].x-v[j].x)*(v[i].x-v[j].x)+(v[i].y-v[j].y)*(v[i].y-v[j].y);
            mx=max(mx,dis);       
        }           
    }
    cout<<fixed<<setprecision(10)<<sqrtl(mx)/2<<nl;

    return 0;
}