#pragma region Header
#ifdef DEBUG
#include "debug.hpp"
#else
#define NDEBUG
#define debug(...)
#define IFD(...)
#endif
#include <utility>
#include <cstdint>
#include <cmath>
#include <cassert>
#include <vector>
#include <array>
#include <deque>
#include <queue>
#include <stack>
#include <tuple>
#include <set>
#include <map>
#include <unordered_map>
#include <bitset>
#include <string>
#include <functional>
#include <algorithm>
#include <numeric>
#include <stdexcept>
#include <iostream>
#include <iomanip>
using namespace std;
using i32 = int32_t;
using i64 = int64_t;
using u32 = uint32_t;
using u64 = uint64_t;
#define rep(i, n) for (int i = 0; i < static_cast<int>(n); ++i)
#define repd(i, n) for (int i = static_cast<int>(n) - 1; i >= 0; --i)
#define FOR(i, a, b) for (int i = static_cast<int>(a); i <= static_cast<int>(b); ++i)
#define FORD(i, b, a) for (int i = static_cast<int>(b); i >= static_cast<int>(a); --i)
template <typename T>
int SZ(T const &x)
{
    return static_cast<int>(x.size());
}
template <class T>
bool chmax(T &a, T const &b)
{
    if (a < b)
    {
        a = b;
        return true;
    }
    return false;
}
template <class T>
bool chmin(T &a, T const &b)
{
    if (b < a)
    {
        a = b;
        return true;
    }
    return false;
}
#pragma endregion

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(15);
    IFD(clog << fixed << setprecision(15));

    int n;
    cin >> n;
    vector x_s(n, 0LL), y_s(n, 0LL);
    rep(i, n)
    {
        cin >> x_s[i] >> y_s[i];
    }

    auto in_cir_1 = [&](auto x, auto y, auto x0, auto y0, auto r) {
        return (x - x0) * (x - x0) + (y - y0) * (y - y0) <= r * r + 1e-12;
    };
    auto in_cir = [&](auto x0, auto y0, auto r) {
        rep(i, n)
        {
            if (not in_cir_1(x_s[i], y_s[i], x0, y0, r))
            {
                return false;
            }
        }
        return true;
    };

    long double res = 1000'000;
    rep(i, n)
    {
        FOR(j, i + 1, n - 1)
        {
            long double r = sqrtl((x_s[j] - x_s[i]) * (x_s[j] - x_s[i]) + (y_s[j] - y_s[i]) * (y_s[j] - y_s[i])) / 2;
            if (in_cir((x_s[i] + x_s[j]) / 2.l, (y_s[i] + y_s[j]) / 2.l, r))
            {
                chmin(res, r);
            }
        }
    }
    rep(i, n)
    {
        FOR(j, i + 1, n - 1)
        {
            FOR(k, j + 1, n - 1)
            {
                i64 det = (x_s[j] - x_s[i]) * (y_s[k] - y_s[j]) - (x_s[k] - x_s[j]) * (y_s[j] - y_s[i]);
                if (det == 0)
                {
                    continue;
                }
                long double x0 = (long double)((y_s[k] - y_s[j]) * (x_s[j] * x_s[j] + y_s[j] * y_s[j] - x_s[i] * x_s[i] - y_s[i] * y_s[i]) - (y_s[j] - y_s[i]) * (x_s[k] * x_s[k] + y_s[k] * y_s[k] - x_s[j] * x_s[j] - y_s[j] * y_s[j])) / 2 / det;
                long double y0 = (long double)(-(x_s[k] - x_s[j]) * (x_s[j] * x_s[j] + y_s[j] * y_s[j] - x_s[i] * x_s[i] - y_s[i] * y_s[i]) + (x_s[j] - x_s[i]) * (x_s[k] * x_s[k] + y_s[k] * y_s[k] - x_s[j] * x_s[j] - y_s[j] * y_s[j])) / 2 / det;
                long double r = sqrtl((x_s[i] - x0) * (x_s[i] - x0) + (y_s[i] - y0) * (y_s[i] - y0));

                // debug((x0 - (x_s[i] + x_s[j]) / 2.l) * (x_s[j] - x_s[i]) + (y0 - (y_s[i] + y_s[j]) / 2.l) * (y_s[j] - y_s[i]));
                // debug((x0 - (x_s[j] + x_s[k]) / 2.l) * (x_s[k] - x_s[j]) + (y0 - (y_s[j] + y_s[k]) / 2.l) * (y_s[k] - y_s[j]));
                // debug(x0 * (x_s[j] - x_s[i]), -(long double)(y_s[j] - y_s[i]) * y0 + ((long double)(y_s[j] * y_s[j] - y_s[i] * y_s[i]) + (x_s[i] + x_s[j]) * (x_s[j] - x_s[i])) / 2.l);
                // debug(x0 * (x_s[k] - x_s[j]), -(long double)(y_s[k] - y_s[j]) * y0 + ((long double)(y_s[k] * y_s[k] - y_s[j] * y_s[j]) + (x_s[j] + x_s[k]) * (x_s[k] - x_s[j])) / 2.l);
                // assert(in_cir_1(x_s[i], y_s[i], x0, y0, r));
                // assert(in_cir_1(x_s[j], y_s[j], x0, y0, r));
                // debug(det, x_s[k], y_s[k], x0, y0, r);
                // assert(in_cir_1(x_s[k], y_s[k], x0, y0, r));

                if (in_cir(x0, y0, r))
                {
                    chmin(res, r);
                }
            }
        }
    }

    cout << res << '\n';

    return 0;
}


Measured memory_bytes: 3796