#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <iostream>
#include <istream>
#include <iterator>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>
#include <tuple>
#include <iomanip>
#include <climits>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
//typedef pair<ll, ll> P;
#define rep(i, n) for(ll i = 0; i < (n); i++)
#define revrep(i, n) for(ll i = (n)-1; i >= 0; i--)
#define pb push_back
#define f first
#define s second
#define chmin(x, y) x = min(x, y);
#define chmax(x, y) x = max(x, y);

//const ll INFL = LLONG_MAX;//10^18 = 2^60
const ll INFL = 1LL<<60;
//const int INF = INT_MAX;
const ll INF = 1 << 30;//10^9
ll MOD = 1000000007;
//ll MOD = 998244353;
double EPS = 1e-10;

vector<ll> dy = {0, 1, 0, -1, 1, 1, -1, -1, 0};
vector<ll> dx = {1, 0, -1, 0, 1, -1, 1, -1, 0};

void pres(double A, ll x = 30){cout << fixed << setprecision(x) << A << endl;}
void BinarySay(ll x, ll y = 60){rep(i, y) cout << (x>>(y-1-i) & 1); cout << endl;}
ll cnt_bit(ll x){return __builtin_popcountll(x);}

ll pow_long(ll x, ll k){
  ll res = 1;
  while(k > 0){
    if(k % 2) res *= x;
    x *= x; k /= 2;
  }
  return res;
}

ll pow_mod(ll x, ll k){
  ll res = 1;
  while(k > 0){
    if(k % 2){
      res *= x; res %= MOD;
    }
    x *= x; x %= MOD;
    k /= 2;
  }
  return res;
}

ll inverse(ll x){return pow_mod(x, MOD - 2);};

ll gcd(ll a, ll b){
    if(b == 0) return a;
    return gcd(b, a % b);
}

ll lcm(ll x, ll y){
  ll res = x / gcd(x, y);
  res *= y;
  return res;
};

//コンビネーション
const int MAXcomb = 200010;
ll fac[MAXcomb], finv[MAXcomb], inv[MAXcomb];
//facはn!,finvは1/n!
//invは逆元
void COMinit(){
    fac[0] = fac[1] = 1;
    finv[0] = finv[1] = 1;
    inv[1] = 1;
    for(int i = 2; i < MAXcomb; i++){
        fac[i] = fac[i-1] * i % MOD;
        inv[i] = MOD - inv[MOD%i] * (MOD/i) % MOD;
        finv[i] = finv[i-1] * inv[i] % MOD;
    }
}
ll comb(int n, int k){
    if(n < k) return 0;
    if(n < 0 || k < 0) return 0;
    return fac[n] * finv[k] % MOD * finv[n-k] % MOD;
}

const int MAXkai = 200010;
ll kai_memo[MAXkai];
ll kai(ll N){
  if(kai_memo[N] != 0) return kai_memo[N];
  if(N <= 1) return 1;
  return kai_memo[N] = N * kai(N-1) % MOD;
}

double dist(double y1, double x1, double y2, double x2){
  return sqrt(pow(y1 - y2, 2.0) + pow(x1 - x2, 2.0));
}

pair<double, double> gaisin(double a, double b, double c, double d, double e, double f){
  //引数はy1, x1, y2, x2, y3, x3の順番
  double a2 = a*a, b2 = b*b, c2 = c*c, d2 = d*d, e2 = e*e, f2 = f*f;
  double py = (f - b) * (a2 + b2 - c2 - d2) - (d - b) * (a2 + b2 - e2 - f2);
  py /= 2.0 * (f - b) * (a - c) - 2.0 * (d - b) * (a - e);
  double px;
  if(d != b){
    px = (2.0 * (a - c) * py - a2 - b2 + c2 + d2) / (d - b) / 2.0;
  }else{
    px = (2.0 * (a - e) * py - a2 - b2 + e2 + f2) / (f - b) / 2.0;
  }
  double r = dist(py, px, a, b);
  return {py, px};
}


void solve(){
  ll N;
  cin >> N;
  vector<double> y(N), x(N);
  rep(i, N) cin >> x[i] >> y[i];
  double ans = 1. * INFL * INFL;
  rep(i, N)for(ll j = i + 1; j < N; j++)for(ll k = j + 1; k < N; k++){
    if(y[i] == y[j] && y[j] == y[k]) continue;
    if(x[i] == x[j] && x[j] == x[k]) continue;
    pair<double, double> p = gaisin(y[i], x[i], y[j], x[j], y[k], x[k]);
    double py = p.f, px = p.s;
    double r = 0;
    rep(t, N){
      r = max(r, dist(py, px, y[t], x[t]));
    }
    ans = min(ans, r);
  }
  rep(i, N)for(ll j = i + 1; j < N; j++){
    double py = (y[i] + y[j]) / 2, px = (x[i] + x[j]) / 2;
    double r = 0;
    rep(t, N){
      r = max(r, dist(py, px, y[t], x[t]));
    }
    ans = min(ans, r);
  }
  pres(ans);
}


int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  solve();
}


Measured memory_bytes: 256