using System;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using System.Text;
using static System.Math;
using static System.Array;
using static AtCoder.Tool;
namespace AtCoder
{
    class AC
    {
        const int MOD = 1000000007;
        const int INF = int.MaxValue / 2;
        const long SINF = long.MaxValue / 2;
        const double EPS = 1e-7;
        static readonly int[] dI = { 0, 1, 0, -1 };
        static readonly int[] dJ = { 1, 0, -1, 0 };
        //static List<List<int>> G = new List<List<int>>();
        //static List<List<Edge>>G = new List<List<Edge>>();
        //static List<Edge> E = new List<Edge>();
        static void Main(string[] args)
        {
            //var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
            //Console.SetOut(sw);
            var cin = new Scanner();

            int N = int.Parse(Console.ReadLine());
            var x = new double[N];
            var y = new double[N];
            for(var i = 0; i < N; i++)
            {
                var p = cin.ReadSplit_Double();
                x[i] = p[0];
                y[i] = p[1];
            }
            if (N == 2) { Console.WriteLine(dist(x[0], y[0], x[1], y[1]) / 2); return; }
            double ans = INF;
            for (var i = 0; i < N - 1; i++)
            {
                for(var j = i + 1; j < N; j++)
                {
                    var px = (x[i] + x[j]) / 2;
                    var py = (y[i] + y[j]) / 2;
                    var ok = true;
                    var r = dist(px, py, x[i], y[i]);
                    for(var k = 0; k < N; k++)
                    {
                        ok &= (dist(px, py, x[k], y[k]) < r + EPS);
                    }
                    if (ok) { ans = Min(ans, r); }
                }
            }
            for(var i = 0; i < N - 2; i++)
            {
                for(var j = i + 1; j < N - 1; j++)
                {
                    for(var k = j + 1; k < N; k++)
                    {
                        double[] pts = new double[6];
                        pts[0] = x[i];pts[1] = y[i];
                        pts[2] = x[j];pts[3] = y[j];
                        pts[4] = x[k];pts[5] = y[k];
                        var t = Center(pts);
                        var px = t.Item1;
                        var py = t.Item2;
                        if ((y[i] - y[k]) * (x[i] - x[j]) - (y[i] - y[j]) * (x[i] - x[k]) == 0 || (x[i] - x[k]) * (y[i] - y[j]) - (x[i] - x[j]) * (y[i] - y[k]) == 0) 
                        {
                            continue;
                        }
                        double r = dist(px, py, x[i], y[i]);
                        var ok = true;
                        for(var l = 0; l < N; l++)
                        {
                            ok &= (dist(px, py, x[l], y[l]) < r + EPS);
                        }
                        if (ok) ans = Min(ans, r);
                    }
                }
            }
            Console.WriteLine(ans);

            //Console.Out.Flush();
        }
        static Tuple<double,double> Center(double[] pts)
        {
            var x1 = pts[0];var y1 = pts[1];
            var x2 = pts[2];var y2 = pts[3];
            var x3 = pts[4];var y3 = pts[5];
            var px = ((y1 - y3) * (y1 * y1 - y2 * y2 + x1 * x1 - x2 * x2) - (y1 - y2) * (y1 * y1 - y3 * y3 + x1 * x1 - x3 * x3)) / (2 * (y1 - y3) * (x1 - x2) - 2 * (y1 - y2) * (x1 - x3));
            var py = ((x1 - x3) * (x1 * x1 - x2 * x2 + y1 * y1 - y2 * y2) - (x1 - x2) * (x1 * x1 - x3 * x3 + y1 * y1 - y3 * y3)) / (2 * (x1 - x3) * (y1 - y2) - 2 * (x1 - x2) * (y1 - y3));
            return new Tuple<double, double>(px, py);

        }
        static double dist(double x1,double y1,double x2,double y2)
        {
            return Sqrt(Pow(x1 - x2, 2) + Pow(y1 - y2, 2));
        }

        struct Edge
        {
            public int from;

            public int to;
            public long dist;
            public Edge(int t, long c)
            {
                from = -1;
                to = t;
                dist = c;
            }
            public Edge(int f, int t, long c)
            {
                from = f;
                to = t;
                dist = c;
            }

        }
    }

    public class Scanner
    {
        public int[] ReadSplitInt()
        {
            return ConvertAll(Console.ReadLine().Split(), int.Parse);
        }
        public long[] ReadSplitLong()
        {
            return ConvertAll(Console.ReadLine().Split(), long.Parse);
        }
        public double[] ReadSplit_Double()
        {
            return ConvertAll(Console.ReadLine().Split(), double.Parse);
        }
    }
    public static class Tool
    {
        static public void Initialize<T>(ref T[] array, T initialvalue)
        {
            for (var i = 0; i < array.Length; i++)
            {
                array[i] = initialvalue;
            }
        }
        static public void Swap<T>(ref T a, ref T b)
        {
            T keep = a;
            a = b;
            b = keep;
        }

        static public void Display<T>(T[,] array2d, int n, int m)
        {
            for (var i = 0; i < n; i++)
            {
                for (var j = 0; j < m; j++)
                {
                    Console.Write($"{array2d[i, j]} ");
                }
                Console.WriteLine();
            }
        }

        static public long LPow(int a, int b)
        {
            return (long)Pow(a, b);
        }
    }
    class Modulo
    {
        private const int M = 1000000007;
        private readonly int[] m_facs;
        public int Mul(int a, int b)
        {
            return (int)(Math.BigMul(a, b) % M);
        }
        public Modulo(int n)
        {
            m_facs = new int[n + 1];
            m_facs[0] = 1;
            for (int i = 1; i <= n; ++i)
            {
                m_facs[i] = Mul(m_facs[i - 1], i);
            }
        }
        public int Fac(int n)
        {
            return m_facs[n];
        }
        public int Pow(int a, int m)
        {
            switch (m)
            {
                case 0:
                    return 1;
                case 1:
                    return a;
                default:
                    int p1 = Pow(a, m / 2);
                    int p2 = Mul(p1, p1);
                    return ((m % 2) == 0) ? p2 : Mul(p2, a);
            }
        }
        public int Div(int a, int b)
        {
            return Mul(a, Pow(b, M - 2));
        }
        public int Ncr(int n, int r)
        {
            if (n < r) { return 0; }
            if (n == r) { return 1; }
            int res = Fac(n);
            res = Div(res, Fac(r));
            res = Div(res, Fac(n - r));
            return res;
        }
        public Modulo() { }
    }
}


Measured memory_bytes: 13268