#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;
long double EPS = 1e-8;

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;
}

long double dist(long double y1, long double x1, long double y2, long double x2){
  return sqrt(pow(y1- y2, 2) + pow(x1 - x2, 2));
}


void solve(){
  ll N;
  cin >> N;
  vector<long double> x(N), y(N);
  long double ANS = 1. * INFL;
  rep(i, N) cin >> x[i] >> y[i];
  rep(i, N)for(ll j = i + 1; j < N; j++)for(ll k = j + 1; k < N; k++){
    long double a = x[i];
    long double b = y[i];
    long double c = x[j];
    long double d = y[j];
    long double e = x[k];
    long double f = y[k];
    long double py = (e - a) * (a * a + b * b - c * c - d * d) - (c - a) * (a * a + b * b - e * e - f * f);
    py /= 2.0 * (e - a) * (b - d) - 2.0 * (c - a) * (b - f);
    long double px;
    if(c != a){
      px = (2.0 * (b - d) * py - a * a - b * b + c * c + d * d) / (c - a) / 2.0;
    }else{
      px = (2.0 * (b - f) * py - a * a - b * b + e * e + f * f) / (e - a) / 2.0;
    }

    long double r = sqrt(pow(px - a, 2.0) + pow(py - b, 2.0));
    bool ok = 1;
    rep(t, N){
      if(ok == 0) break;
      if(dist(py, px, y[t], x[t]) - r > EPS) ok = 0;
    }
    if(ok) ANS = min(ANS, r);
  }

  rep(i, N)for(ll j = i + 1; j < N; j++){
    long double py = (y[i] + y[j]) / 2;
    long double px = (x[i] + x[j]) / 2;
    long double r = dist(y[i], x[i], py, px);
    bool ok = 1;
    rep(t, N){
      if(ok == 0) break;
      if(dist(py, px, y[t], x[t]) - r > 0) ok = 0;
    }
    if(ok) ANS = min(ANS, r);
  }
  pres(ANS);
}


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


Measured memory_bytes: 256