#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;
typedef tree<pair<int,int>, null_type, less<pair<int,int>>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;

#define scan(x) do{while((x=getchar())<'0'); for(x-='0'; '0'<=(_=getchar()); x=(x<<3)+(x<<1)+_-'0');}while(0)
char _;
#define complete_unique(a) a.erase(unique(a.begin(),a.end()),a.end())
#define all(a) a.begin(),a.end()
#define println printf("\n");
#define readln(x) getline(cin,x);
#define pb push_back
#define endl "\n"
#define MOD 1000000007
#define mp make_pair
#define fastio cin.tie(0); cin.sync_with_stdio(0);

typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
typedef unordered_map<int,int> umii;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<int,pii> triple;
typedef int8_t byte;

ll gcd(ll a, ll b) {return b == 0 ? a : gcd(b, a % b);}
ll fpow(ll  b, ll exp, ll mod){if(exp == 0) return 1;ll t = fpow(b,exp/2,mod);if(exp&1) return t*t%mod*b%mod;return t*t%mod;}
ll divmod(ll i, ll j, ll mod){i%=mod,j%=mod;return i*fpow(j,mod-2,mod)%mod;}

int num_points;
double ans=INT_MAX;
vector<pll> points;

inline double calcDis(double x, double y, double tx, double ty){
    return sqrt(abs(x-tx)*abs(x-tx)+abs(y-ty)*abs(y-ty));
}

inline pair<double,double> getCenter(pair<double,double> a, pair<double,double> b, pair<double,double> c){
    pair<double,double> mid1 = mp((a.first+b.first)/2,(a.second+b.second)/2);
    pair<double,double> mid2 = mp((b.first+c.first)/2,(b.second+c.second)/2);

    double slope1 = -1.0/((a.second-b.second)/(a.first-b.first));
    double slope2 = -1.0/((b.second-c.second)/(b.first-c.first));

    double b1 = mid1.second-slope1*mid1.first;
    double b2 = mid2.second-slope2*mid2.first;

    pair<double,double> center = mp((b2-b1)/(slope1-slope2),((b2-b1)/(slope1-slope2))*slope1+b1);
    return center;
}

void solve1(int idx, vector<pll> check){
    if(check.size() == 2){
        double x = (double)(check[0].first+check[1].first)/2, y = (double)(check[0].second+check[1].second)/2, temp = 0;
        for(pll c:points){
            double dis = calcDis(c.first,c.second,x,y);
            temp = max(temp,dis);
        }
        ans = min(ans,temp);
        return;
    }
    if(idx == num_points) return;
    solve1(idx+1,check);
    check.pb(points[idx]);
    solve1(idx+1,check);
}

void solve2(int idx, vector<pll> check){
    if(check.size() == 3){
        sort(check.begin(),check.end());
        pair<double,double> cen = getCenter(check[0],check[1],check[2]);
        double x = cen.first, y = cen.second, temp = 0;
        if(isnan((ld)x) || isnan((ld)y)) return;
        for(pll c:points){
            double dis = calcDis(c.first,c.second,x,y);
            temp = max(temp,dis);
        }
        ans = min(ans,temp);
        return;
    }
    if(idx == num_points) return;
    solve2(idx+1,check);
    check.pb(points[idx]);
    solve2(idx+1,check);
}

int main(){
    scanf("%d",&num_points);
    if(num_points == 1) return 0*printf("0\n");
    for(int i=1; i<=num_points; i++){
        ll x,y; scanf(" %lld %lld",&x,&y);
        points.pb(mp(x,y));
    }
    vector<pll> v;
    solve1(0,v);
    if(num_points == 2) return 0*printf("%.6f\n",ans);
    solve2(0,v);
    printf("%.6f\n",ans);
}

Measured memory_bytes: 256