/*
* Copyright (c) 2024 Emon Thakur
* All rights reserved.
*/
#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
using minheap = priority_queue<long long, vector<long long>, greater<long long>>;
typedef tree<int, null_type, greater_equal<int>, rb_tree_tag, tree_order_statistics_node_update> pbds; // find_by_order, order_of_key
#define ll long long
#define ld long double
#define MOD 1000000007
#define pie 2*(acos(0.0))
#define yes cout<<"YES\n"
#define no cout<<"NO\n"
#define pb push_back
#define endl '\n'
#define lcm(a,b) (a*b)/(__gcd<ll>(a,b))
#define print(v) for(auto e:v) cout<<e<<" "; cout<<endl;
#define printp(v) for(auto e:v) cout<<e.first<<" "<<e.second<<endl;
#define srt(v) sort(v.begin(),v.end())
#define rsrt(v) sort(v.rbegin(),v.rend())
#define life_is_a_race ios::sync_with_stdio(false); cin.tie(nullptr);
void solve(int tc)
{
//cout<<"Case "<<tc<<": ";
int n; cin >> n;
vector<pair<ld,ld>> v(n);
for(int i=0;i<n;i++)
{
cin>>v[i].first >> v[i].second;
}
ld ans = 1000000000,r,x,y,d;
for(int i=0;i<n;i++)
{
for(int j=i+1;j<n;j++)
{
x = (v[i].first+v[j].first)/2;
y = (v[i].second+v[j].second)/2;
r = sqrtl((v[i].first-v[j].first)*(v[i].first-v[j].first)+(v[i].second-v[j].second)*(v[i].second-v[j].second)) / 2;
bool ok = true;
for(int k=0;k<n;k++)
{
if(k==i || k==j) continue;
d = sqrtl((x-v[k].first)*(x-v[k].first) + (y-v[k].second)*(y-v[k].second))/2;
if(d > r)
{
ok = false;
break;
}
}
if(ok) ans = min(ans , r);
}
}
cout<<fixed<<setprecision(10)<<ans;
}
int main()
{
life_is_a_race
int t=1;
//cin>>t;
for(int i=1;i<=t;i++) solve(i);
}