#include <iostream>
#include <array>
#include <vector>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <algorithm>
#include <math.h>
#include <string>
#include <climits>
#include <assert.h>
#include <iomanip>
#include <bitset>
#include <queue>
#include <deque>
#include <stack>
#include <functional>
#include <fstream>
#include <random>

#define LEN(x) (long long)(x.size())
#define FOR(i, a, n) for(int i=(a);i<(n); ++i)
#define FOE(i, a) for(auto i : a)
#define ALL(c) (c).begin(), (c).end()
#define RALL(c) (c).rbegin(), (c).rend()
#define SUM(x) std::accumulate(ALL(x), 0LL)
#define MIN(v) *std::min_element(v.begin(), v.end())
#define MAX(v) *std::max_element(v.begin(), v.end())
#define EXIST(v, x) (std::find(v.begin(), v.end(), x) != v.end())
#define BIT_COUNT(bit) (__builtin_popcount(bit))

using LL = long long;

template<typename T>
std::vector<T> make_v(size_t a) { return std::vector<T>(a); }

template<typename T, typename... Ts>
auto make_v(size_t a, Ts... ts) { return std::vector<decltype(make_v<T>(ts...))>(a, make_v<T>(ts...)); }    // C++14
template<typename T, typename V>
typename std::enable_if<std::is_class<T>::value == 0>::type fill_v(T &t, const V &v) { t = v; }

template<typename T, typename V>
typename std::enable_if<std::is_class<T>::value != 0>::type fill_v(T &t, const V &v) { for (auto &e:t) fill_v(e, v); }

template<class T>
inline T ceil(T a, T b) { return (a + b - 1) / b; }

void print() { std::cout << std::endl; }

template<class Head, class... Tail>
void print(Head &&head, Tail &&... tail) {
    std::cout << head;
    if (sizeof...(tail) != 0) { std::cout << " "; }
    print(std::forward<Tail>(tail)...);
}

template<class T>
void print(std::vector<T> &v) {
    for (auto &a : v) {
        std::cout << a;
        if (&a != &v.back()) { std::cout << " "; }
    }
    std::cout << std::endl;
}

template<class T>
void print(std::vector<std::vector<T>> &vv) { for (auto &v : vv) { print(v); }}

void debug() { std::cerr << std::endl; }

template<class Head, class... Tail>
void debug(Head &&head, Tail &&... tail) {
    std::cerr << head;
    if (sizeof...(tail) != 0) { std::cerr << " "; }
    print(std::forward<Tail>(tail)...);
}

template<class T>
void debug(std::vector<T> &v) {
    for (auto &a : v) {
        std::cerr << a;
        if (&a != &v.back()) { std::cerr << " "; }
    }
    std::cerr << std::endl;
}

template<class T>
void debug(std::vector<std::vector<T>> &vv) { for (auto &v : vv) { print(v); }}

inline bool inside(long long y, long long x, long long H, long long W) { return 0 <= y and y < H and 0 <= x and x < W; }

template<class T>
inline double euclidean_distance(T y1, T x1, T y2, T x2) { return sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2)); }

template<class T>
inline double manhattan_distance(T y1, T x1, T y2, T x2) { return abs(x1 - x2) + abs(y1 - y2); }

template<typename T>
T &chmin(T &a, const T &b) { return a = std::min(a, b); }

template<typename T>
T &chmax(T &a, const T &b) { return a = std::max(a, b); }

bool is_bit_on(const unsigned long long bit, const unsigned int i) { return (bit >> i) & 1u; }

unsigned long long bit_set(const unsigned long long bit, const unsigned int i, const unsigned int b) {
    assert(b == 0 or b == 1);
    if (b == 0) { return bit & ~(1ull << i); }
    else { return bit | (1ull << i); }
}

// 初項s交差d長さnの数列の和
long long sum_of_arithmetic_progression(long long s, long long d, long long n) {
    return n * (2 * s + (n - 1) * d) / 2;
}

// xが2の階乗かどうか判定
bool is_power_of_two(long long x) {
    return !(x & (x - 1));
}

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

long long gcd(std::vector<long long> &v) {
    long long ans = v[0];
    for (int i = 1; i < (int) v.size(); ++i) {
        ans = gcd(ans, v[i]);
    }
    return ans;
}

long long lcm(long long a, long long b) {
    long long g = gcd(a, b);
    return a / g * b;
}

const int INF = 1u << 30u;  // 1,073,741,824
const long long LINF = 1ull << 60u;
const double EPS = 1e-9;
const long double PI = acos(-1.0);
const std::vector<int> dy2 = {0, 1}, dx2 = {1, 0};
const std::vector<int> dy4 = {0, 1, 0, -1}, dx4 = {1, 0, -1, 0};
const std::vector<int> dy8 = {0, -1, 0, 1, 1, -1, -1, 1}, dx8 = {1, 0, -1, 0, 1, 1, -1, -1};

class Point {
public:
    double x;
    double y;

    Point(): x(0), y(0) {}
    Point(double x, double y) : x(x), y(y) {}
};

class SmallestEnclosingCircle {
private:
    double min_x;
    double max_x;
    double min_y;
    double max_y;

public:
    SmallestEnclosingCircle() {}

    // 最小包含円の半径
    double solve(const std::vector<Point> &points) {
        this->min_x = this->max_x = points[0].x;
        this->min_y = this->max_y = points[0].y;

        for (const auto &p : points) {
            this->min_x = std::min(this->min_x, p.x);
            this->max_x = std::max(this->max_x, p.x);
            this->min_y = std::min(this->min_y, p.y);
            this->max_y = std::max(this->max_y, p.y);
        }

        double l = this->min_x - 1.0;
        double r = this->max_x + 1.0;

        // x座標で3分探索
        for (int _ = 0; _ < 100; ++_) {
            const double c1 = (l * 2 + r) / 3.0;
            const double c2 = (l + r * 2) / 3.0;

            if (g(c1, points) > g(c2, points)) {
                l = c1;
            } else {
                r = c2;
            }
        }

        return g(l, points);
    }

private:

    // 点aと点bの距離
    double dist(const Point &a, const Point &b) {
        double dx = a.x - b.x;
        double dy = a.y - b.y;
        return sqrt(dx * dx + dy * dy);
    }

    // nowから最も遠い点までの距離
    double max_distance(const Point &now, const std::vector<Point> &points) {
        double res = 0;
        for (const auto p : points) {
            res = std::max(res, dist(now, p));
        }
        return res;
    }

    // x座標を決めたときの，y軸の距離を最小化
    double g(const double x, const std::vector<Point> &points) {
        double l = this->min_y - 1.0;
        double r = this->max_y + 1.0;

        for (int _ = 0; _ < 100; ++_) {
            double c1 = (l * 2 + r) / 3;
            double c2 = (l + r * 2) / 3;

            if (max_distance(Point(x, c1), points) > max_distance(Point(x, c2), points)) {
                l = c1;
            } else {
                r = c2;
            }
        }

        return max_distance(Point(x, l), points);
    }
};

using namespace std;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    LL N;
    cin >> N;

    auto points = make_v<Point>(N);
    FOR(i, 0, N) {
        cin >> points[i].x >> points[i].y;
    }

    SmallestEnclosingCircle sec;

    cout << fixed << setprecision(15) << sec.solve(points) << endl;

    return 0;
}

Measured memory_bytes: 3808