#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <iostream>
#include <fstream>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cstring>
#include <cassert>
#include <string>
#include <vector>
#include <utility>
#include <complex>
#include <set>
#include <map>
#include <unordered_map>
#include <queue>
#include <stack>
#include <deque>
#include <tuple>
#include <bitset>
#include <limits>
#include <algorithm>
#include <array>
#include <random>
#include <complex>
#include <regex>
using namespace std;
typedef long double ld;
typedef long long ll;
typedef vector<int> vint;
typedef vector<ll> vll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<double, double> pdd;
typedef complex<ld> compd;
#define quickIO()	{cin.tie(0);	cout.sync_with_stdio(false);}
#define reach(i,a)	for(auto i:a)
#define rep(i,n)	for(int i=0;i<((int)n);i++)
#define REP(i,n)	for(int i=0;i<=((int)n);i++)
#define srep(i,a,n)	for(int i=a;i<((int)n);i++)
#define SREP(i,a,n)	for(int i=a;i<=((int)n);i++)
#define rrep(i,n)	for(int i=n-1;i>=0;i--)
#define RREP(i,n)	for(int i=n;i>=0;i--)
#define all(a)	(a).begin(),(a).end()
#define mp(a,b)	make_pair(a,b)
#define mt	make_tuple
#define pb	push_back
template<typename T> istream& operator >> (istream& is, vector<T>& vec) {
	for (T& x : vec)	is >> x;
	return is;
}
template<typename T> ostream& operator << (ostream& os, vector<T>& vec) {
	os << "[";
	rep(i, vec.size())	os << (i ? ", " : "") << vec[i];
	os << "]";
	return os;
}
template<typename T> istream& operator >> (istream& is, pair<T, T>& p) {
	is >> p.first >> p.second;
	return is;
}
template<typename T> ostream& operator << (ostream& os, pair<T, T>& p) {
	os << p.first << " " << p.second;
	return os;
}
template<typename T> bool operator < (vector<T>& a, vector<T>& b) {
	rep(i, a.size()) {
		if (i == b.size())	return false;
		if (a[i] < b[i])	return true;
		else if (a[i] > b[i])	return false;
	}
	return false;
}
template<typename T> bool operator > (vector<T>& a, vector<T>& b) {
	rep(i, a.size()) {
		if (i == b.size())	return true;
		if (a[i] < b[i])	return false;
		else if (a[i] > b[i])	return true;
	}
	return false;
}
int bitcnt(ll x) {
	x = ((x & 0xAAAAAAAAAAAAAAAA) >> 1) + (x & 0x5555555555555555);
	x = ((x & 0xCCCCCCCCCCCCCCCC) >> 2) + (x & 0x3333333333333333);
	x = ((x & 0xF0F0F0F0F0F0F0F0) >> 4) + (x & 0x0F0F0F0F0F0F0F0F);
	x = ((x & 0xFF00FF00FF00FF00) >> 8) + (x & 0x00FF00FF00FF00FF);
	x = ((x & 0xFFFF0000FFFF0000) >> 16) + (x & 0x0000FFFF0000FFFF);
	x = ((x & 0xFFFFFFFF00000000) >> 32) + (x & 0x00000000FFFFFFFF);
	return x;
}
int bitcnt(int x) {
	x = ((x & 0xAAAAAAAA) >> 1) + (x & 0x55555555);
	x = ((x & 0xCCCCCCCC) >> 2) + (x & 0x33333333);
	x = ((x & 0xF0F0F0F0) >> 4) + (x & 0x0F0F0F0F);
	x = ((x & 0xFF00FF00) >> 8) + (x & 0x00FF00FF);
	x = ((x & 0xFFFF0000) >> 16) + (x & 0x0000FFFF);
	return x;
}
ll sqrtll(ll x) {
	ll left = 0, right = x;
	rep(i, 100) {
		ll mid = (left + right) >> 1;
		if (mid * mid <= x)	left = mid;
		else	right = mid;
	}
	return left;
}
ll gcd(ll a, ll b) {
	return b == 0 ? a : gcd(b, a % b);
}
#define debug(x)	printf("Case #%d: ", x)
#define DEBUG 0
const ld infl = 1e100;
const ll mod = 1e9 + 7;
const ld eps = 1e-9;
const ll inf = 1e15;
const int dx[] = { 1,0,-1,0,0 };
const int dy[] = { 0,1,0,-1,0 };

vector<tuple<int, int, int>> dat;

double dist(int x1, int y1, int x2, int y2) {
	return sqrt(pow(x1 - x2, 2) + pow(y1 - y2, 2));
}
double dist(int x, int y, complex<double> target) {
	return sqrt(pow(x - target.real(), 2) + pow(y - target.imag(), 2));
}

complex<double> rotatePoint(complex<double> base, complex<double> target, double theta) {
	target -= base;
	target *= complex<double>(cos(theta), sin(theta));
	target += base;
	return target;
}

vector<complex<double>> searchPoints(int i, int j, double t) {
	int x1, y1, c1, x2, y2, c2;
	tie(x1, y1, c1) = dat[i];
	tie(x2, y2, c2) = dat[j];
	double r1 = t / c1;
	double r2 = t / c2;
	double d = dist(x1, y1, x2, y2);
	complex<double> dif_vec = complex<double>((double)x2 - x1, (double)y2 - y1);
	if (r1 + eps > d) {
		if (r1 > d + r2 + eps)	return {};
		else if (r1 + eps > d + r2) {
			// only one point
			complex<double> res = complex<double>(x1, y1) + dif_vec * (r1 / d);
			return { res };
		}
		else if (r1 + d > r2 + eps) {
			// two points
			complex<double> base = complex<double>(x1, y1);
			complex<double> target = base + dif_vec * (r1 / d);
			// r2^2 = d^2 + r1^2 -2dr1 * cos\theta
			double theta = acos((pow(d, 2) + pow(r1, 2) - pow(r2, 2)) / (2 * d * r1));
			complex<double> res1 = rotatePoint(base, target, theta);
			complex<double> res2 = rotatePoint(base, target, -theta);
			return { res1, res2 };
		}
		else if (r1 + d + eps > r2) {
			// only one point
			complex<double> res = complex<double>(x1, y1) - dif_vec * (r1 / d);
			return { res };
		}
		else	return {};
	}
	else {
		if (r1 + r2 + eps < d) return {};
		else if (r1 + r2 < d + eps) {
			complex<double> res = complex<double>(x1, y1) + dif_vec * (r1 / d);
			return { res };
		}
		else if (d + r1 > r2 + eps) {
			complex<double> base = complex<double>(x1, y1);
			complex<double> target = base + dif_vec * (r1 / d);
			double theta = acos((pow(d, 2) + pow(r1, 2) - pow(r2, 2)) / (2 * r1 * d));
			complex<double> res1 = rotatePoint(base, target, theta);
			complex<double> res2 = rotatePoint(base, target, -theta);
			return { res1, res2 };
		}
		else if (d + r1 + eps < r2) {
			complex<double> res = complex<double>(x1, y1) - dif_vec * (r1 / d);
			return { res };
		}
		else	return {};
	}
}

int main() {
	int n, k;	cin >> n >> k;
	dat.resize(n);
	rep(i, n) {
		int x, y, c;	cin >> x >> y >> c;
		dat[i] = mt(x, y, c);
	}
	if (k == 1) {
		cout << 0 << endl;
		return 0;
	}
	double left = 0, right = 200000;
	rep(t, 100) {
		double mid = (left + right) / 2;
		vector<complex<double>> targets;
		rep(i, n) {
			int x, y, c;	tie(x, y, c) = dat[i];
			targets.push_back(complex<double>(x, y));
		}
		rep(i, n) {
			srep(j, i + 1, n) {
				vector<complex<double>> add = searchPoints(i, j, mid);
				targets.insert(targets.end(), add.begin(), add.end());
			}
		}
		int maxNum = 0;
		for (auto it : targets) {
			int cnt = 0;
			rep(i, n) {
				int x, y, c;	tie(x, y, c) = dat[i];
				if (dist(x, y, it) < mid / c + eps) {
					cnt++;
				}
			}
			maxNum = max(maxNum, cnt);
		}
		if (maxNum >= k) right = mid;
		else	left = mid;
	}
	printf("%lf\n", right);
	return 0;
}


Measured memory_bytes: 640