using System;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using System.Text;
using System.Numerics;
using static System.Math;
using static System.Array;
using static AtCoder.Tool;
namespace AtCoder
{
    class AC
    {
        //const int MOD = 1000000007;
        const int MOD = 998244353;
        const int INF = int.MaxValue / 2;
        const long SINF = long.MaxValue / 2;
        const double EPS = 1e-8;
        static readonly int[] dI = { 0, 1, 0, -1, 1, -1, -1, 1 };
        static readonly int[] dJ = { 1, 0, -1, 0, 1, 1, -1, -1 };
        //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 IO_ShortCut();

            int N, K;
            cin.Input(out N, out K);
            var x = new double[N];
            var y = new double[N];
            var c = new double[N];
            for (var i = 0; i < N; i++) cin.Input(out x[i], out y[i], out c[i]);
            double x1 = 0, y1 = 0, x2 = 0, y2 = 0;

            Func<int, int, double> dist = (a, b) => Sqrt(Pow(x[a] - x[b], 2) + Pow(y[a] - y[b], 2));
            Func<int, int, double, int> pts = (a, b, time) =>
            {
                double ra = time / c[a];
                double rb = time / c[b];
                double d = dist(a, b);
                if (!(Abs(ra - rb) <= d + EPS && d + EPS <= ra + rb)) { return -1; }
                var dx = (x[a] - x[b]);
                var dy = (y[a] - y[b]);
                //cin.Out_Sep(dx, dy);
                var p = (rb * rb - ra * ra + d * d) / (2 * d);
                var cx = x[b] + (dx / d * p);
                var cy = y[b] + (dy / d * p);
                //cin.Out_Sep(cx, cy);

                var q = Sqrt(rb * rb - p * p);
                //cin.Out_Sep(p, d, q);
                x1 = cx + (-dy / d * q);
                y1 = cy + (dx / d * q);
                x2 = cx + (dy / d * q);
                y2 = cy + (-dx / d * q);

                return 0;
            };
            double L = 0;
            double R = 1e9;
            while (R - L > EPS)
            {
                var mid = (R + L) / 2;
                var ok = false;
                for(var i = 0; i < N - 1; i++)
                {
                    for(var j = i + 1; j < N; j++)
                    {
                        if (pts(i, j, mid) == -1) continue;
                        int[] cn = { 0, 0 };
                        for(var k = 0; k < N; k++)
                        {
                            if (Sqrt(Pow(x[k] - x1, 2) + Pow(y[k] - y1, 2)) <= (mid / c[k]) + EPS)
                            {
                                cn[0]++;
                            }
                            if(Sqrt(Pow(x[k] - x2, 2) + Pow(y[k] - y2, 2)) <= (mid / c[k]) + EPS)
                            {
                                cn[1]++;
                            }
                        }
                        ok |= cn[0] >= K || cn[1] >= K;
                    }
                }
                for(var i = 0; i < N; i++)
                {
                    int cnt = 0;
                    for(var j = 0; j < N; j++)
                    {
                        if (Sqrt(Pow(x[i] - x[j], 2) + Pow(y[i] - y[j], 2)) <= mid / c[j] + EPS)
                        {
                            cnt++;
                        }
                    }
                    ok |= cnt >= K;
                }
                if (ok) R = mid;
                else L = mid;
            }
            cin.OutL(L);

            //Console.Out.Flush();
        }
        
        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;
            }
        }
        
    }
    
    class IO_ShortCut
    {
        public IO_ShortCut() { }
        public string[] ReadSplit => Console.ReadLine().Split();
        public int[] ReadSplitInt => ConvertAll(Console.ReadLine().Split(), int.Parse);
        public long[] ReadSplitLong => ConvertAll(Console.ReadLine().Split(), long.Parse);
        public double[] ReadSplit_Double => ConvertAll(Console.ReadLine().Split(), double.Parse);
        public string Str => Console.ReadLine();
        public int Int => int.Parse(Console.ReadLine());
        public long Long => long.Parse(Console.ReadLine());
        public double Double => double.Parse(Console.ReadLine());
        public T Conv<T>(string input) => (T)Convert.ChangeType(input, typeof(T));
        public void Input<T>(out T a) => a = Conv<T>(Console.ReadLine());
        public void Input<T, U>(out T a, out U b)
        { var q = ReadSplit;a = Conv<T>(q[0]);b = Conv<U>(q[1]); }
        public void Input<T, U, V>(out T a, out U b, out V c)
        { var q = ReadSplit;a = Conv<T>(q[0]);b = Conv<U>(q[1]);c = Conv<V>(q[2]); }
        public void Input<T, U, V, W>(out T a, out U b, out V c, out W d)
        { var q = ReadSplit; a = Conv<T>(q[0]); b = Conv<U>(q[1]); c = Conv<V>(q[2]);d = Conv<W>(q[3]); }

        public void OutL(object s) => Console.WriteLine(s);
        public void Out_Sep<T>(IEnumerable<T> s) => Console.WriteLine(string.Join(" ", s));
        public void Out_Sep<T>(IEnumerable<T> s, string sep) => Console.WriteLine(string.Join($"{sep}", s));
        public void Out_Sep(params object[] s) => Console.WriteLine(string.Join(" ", s));
        public void Out_One(object s) => Console.Write($"{s} ");
        public void Out_One(object s, string sep) => Console.Write($"{s}{sep}");
    }
    public static class Tool
    {
        static public void Initialize<T>(ref T[] array, T initialvalue)
        {
            array = ConvertAll(array, x => initialvalue);
        }
        static public void Swap<T>(ref T a, ref T b)
        {
            T keep = a;
            a = b;
            b = keep;
        }
        static public void Display<T>(T[,] array2d, int n, int m)
        {
            for (var i = 0; i < n; i++)
            {
                for (var j = 0; j < m; j++)
                {
                    Console.Write($"{array2d[i, j]} ");
                }
                Console.WriteLine();
            }
        }
        static public long LPow(int a, int b) => (long)Pow(a, b);
    }
    class Modulo
    {
        private int M;
        private readonly long[] m_facs;
        public long Mul(long a, long b)
        {
            return ((a * b) % M);
        }
        public Modulo(long n, int m)
        {
            M = m;
            m_facs = new long[n + 1];
            m_facs[0] = 1;
            for (long i = 1; i <= n; ++i)
            {
                m_facs[i] = Mul(m_facs[i - 1], i);
            }
        }
        public long Fac(long n)
        {
            return m_facs[n];
        }
        public long Pow(long a, long m)
        {
            switch (m)
            {
                case 0:
                    return 1L;
                case 1:
                    return a;
                default:
                    long p1 = Pow(a, m / 2);
                    long p2 = Mul(p1, p1);
                    return ((m % 2) == 0) ? p2 : Mul(p2, a);
            }
        }
        public long Div(long a, long b)
        {
            return Mul(a, Pow(b, M - 2));
        }
        public long Ncr(long n, long r)
        {
            if (n < r) { return 0; }
            if (n == r) { return 1; }
            long res = Fac(n);
            res = Div(res, Fac(r));
            res = Div(res, Fac(n - r));
            return res;
        }
    }
}


Measured memory_bytes: 13268