#include <iostream>
#include <bits/stdc++.h>

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep_r(i, n) for (int i = n - 1; i >= 0; i--)
#define rep1(i, n) for (int i = 1; i <= (int)(n); i++)
#define REP(i, n) for (int i = 0, i##_len = (n); i < i##_len; ++i)
#define all(x) (x).begin(), (x).end()
#define SZ(x) ((ll)(x).size())
#define bit(n) (1LL << (n))
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end());

#define INF bit(60)
#define pb push_back
#define mod 1000000007

using namespace std;
using uif = uint_fast64_t;
using ll = long long int;
using tTree = __gnu_pbds::tree<ll, __gnu_pbds::null_type, less<ll>, __gnu_pbds::rb_tree_tag, __gnu_pbds::tree_order_statistics_node_update>;

ll dx[4] = {1, 0, -1, 0};
ll dy[4] = {0, 1, 0, -1};

#define FACSIZE 200002

ll invfac[FACSIZE];
ll fac[FACSIZE];

template <class T>
bool chmax(T &, const T &);
template <class T>
bool chmin(T &, const T &);
ll gcd(ll, ll);
ll powLL(ll x, ll y);

ll mod_pow(ll, ll);
ll mod_add(ll, ll);
ll mod_mul(ll, ll);
ll mod_div(ll, ll);
ll comb(ll, ll);
void make_fact(ll);
void make_invfact(ll);
void fact_init();

using ld = long double;
using P = std::complex<ld>;
const ld eps = 1e-10;
ld cross(const P &a, const P &b) { return a.real() * b.imag() - a.imag() * b.real(); }

template <class iter>
std::pair<P, ld> min_ball(iter left, iter right, int seed = 1333)
{
  const int n = right - left;

  assert(n >= 1);
  if (n == 1)
  {
    return {*left, ld(0)};
  }

  std::mt19937 mt(seed);
  std::shuffle(left, right, mt);
  // std::random_shuffle(left, right); // simple but deprecated

  iter ps = left;
  using circle = std::pair<P, ld>;

  auto make_circle_3 = [](const P &a, const P &b, const P &c) -> circle {
    ld A = std::norm(b - c), B = std::norm(c - a), C = std::norm(a - b),
       S = cross(b - a, c - a);
    P p = (A * (B + C - A) * a + B * (C + A - B) * b + C * (A + B - C) * c) / (4 * S * S);
    ld r2 = std::norm(p - a);
    return {p, r2};
  };

  auto make_circle_2 = [](const P &a, const P &b) -> circle {
    P c = (a + b) / (ld)2;
    ld r2 = std::norm(a - c);
    return {c, r2};
  };

  auto in_circle = [](const P &a, const circle &c) -> bool {
    return std::norm(a - c.first) <= c.second + eps;
  };

  circle c = make_circle_2(ps[0], ps[1]);

  // MiniDisc
  for (int i = 2; i < n; ++i)
  {
    if (!in_circle(ps[i], c))
    {
      // MiniDiscWithPoint
      c = make_circle_2(ps[0], ps[i]);
      for (int j = 1; j < i; ++j)
      {
        if (!in_circle(ps[j], c))
        {
          // MiniDiscWith2Points
          c = make_circle_2(ps[i], ps[j]);
          for (int k = 0; k < j; ++k)
          {
            if (!in_circle(ps[k], c))
            {
              c = make_circle_3(ps[i], ps[j], ps[k]);
            }
          }
        }
      }
    }
  }
  return c;
}

int main(void)
{
  ll n;
  cin >> n;
  vector<P> vec(n);
  rep(i, n)
  {
    ll x, y;
    cin >> x >> y;
    vec[i] = complex<ld>(x, y);
  }

  auto ans = min_ball(begin(vec), end(vec));

  cout << setprecision(20) << sqrt(ans.second) << endl;

  return 0;
}

ll mod_pow(ll x, ll r)
{
  if (r == 0)
    return 1;
  else if (r == 1)
    return x % mod;
  else if (r % 2 == 0)
  {
    ll t = mod_pow(x, r / 2) % mod;
    return mod_mul(t, t);
  }
  else
  {
    ll t = mod_pow(x, r / 2) % mod;
    ll k = mod_mul(t, t);
    return (k % mod) * (x % mod);
  }
}
ll mod_add(ll a, ll b)
{
  return ((a % mod) + (b % mod)) % mod;
}

ll mod_mul(ll a, ll b)
{
  return ((a % mod) * (b % mod)) % mod;
}

ll mod_div(ll a, ll b)
{
  return mod_mul(a, mod_pow(b, mod - 2));
}

void fact_init()
{
  make_fact(FACSIZE - 1);
  make_invfact(FACSIZE);
}

void make_fact(ll n)
{
  fac[0] = 1;
  rep(i, n)
  {
    fac[i + 1] = mod_mul(fac[i], i + 1);
  }
}

void make_invfact(ll n)
{
  invfac[n] = mod_pow(fac[n], mod - 2);
  for (int i = n - 1; i >= 0; i--)
  {
    invfac[i] = mod_mul(invfac[i + 1], i + 1);
  }
}

ll comb(ll n, ll r)
{

  return mod_mul(mod_mul(fac[n], invfac[r]), invfac[n - r]);
}
template <class T>
bool chmax(T &a, const T &b)
{
  if (a < b)
  {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
bool chmin(T &a, const T &b)
{
  if (b < a)
  {
    a = b;
    return 1;
  }
  return 0;
}

ll qp(ll a, ll b)
{
  ll ans = 1LL;
  do
  {
    if (b & 1LL)
      ans = 1LL * mod_mul(ans, a) % mod;
    a = 1LL * mod_mul(a, a) % mod;
  } while (b >>= 1LL);
  return ans;
}
ll qp(ll a, ll b, ll mo)
{
  ll ans = 1LL;
  do
  {
    if (b & 1LL)
      ans = 1LL * (ans % mo) * (a % mo);
    a = 1LL * (a % mo) * (a % mo);
  } while (b >>= 1LL);
  return ans;
}
ll gcd(ll a, ll b)
{
  return b ? gcd(b, a % b) : a;
}
ll powLL(ll x, ll y)
{
  ll ans = 1LL;
  for (ll i = 0LL; i < y; i++)
    ans *= x;
  return ans;
}


Measured memory_bytes: 256