#include<iostream>
#include<algorithm>
#include<vector>
#include<queue>
#include<stack>
#include<list>
#include<set>
#include<string>
#include<iomanip>
#include<math.h>
#include<bitset>
#include<functional>
#include<map>
#include<complex>
#include<random>
using namespace std;
typedef long long ll;
#define pb(x) push_back(x)
#define mp(a,b) make_pair(a,b)
#define all(x) x.begin(),x.end()
#define lscan(x) scanf("%I64d",&x)
#define lprint(x) printf("%I64d",x)
ll gcd(ll a, ll b) {
	int c = a % b;
	while (c != 0) {
		a = b;
		b = c;
		c = a % b;
	}
	return b;
}
long long extGCD(long long a, long long b, long long &x, long long &y) {
	if (b == 0) {
		x = 1;
		y = 0;
		return a;
	}
	long long d = extGCD(b, a%b, y, x);
	y -= a / b * x;
	return d;
}

struct UnionFind {
	vector< int > data;

	UnionFind(int sz) {
		data.assign(sz, -1);
	}

	bool unite(int x, int y) {
		x = find(x), y = find(y);
		if (x == y) return (false);
		if (data[x] > data[y]) swap(x, y);
		data[x] += data[y];
		data[y] = x;
		return (true);
	}

	int find(int k) {
		if (data[k] < 0) return (k);
		return (data[k] = find(data[k]));
	}

	int size(int k) {
		return (-data[find(k)]);
	}
};

ll M = 1000000007;

vector<ll> fac(2000011); //n!(mod M)
vector<ll> ifac(2000011); //k!^{M-2} (mod M)

ll mpow(ll x, ll n) {
	ll ans = 1;
	while (n != 0) {
		if (n & 1) ans = ans * x % M;
		x = x * x % M;
		n = n >> 1;
	}
	return ans;
}
ll mpow2(ll x, ll n, ll mod) {
	ll ans = 1;
	while (n != 0) {
		if (n & 1) ans = ans * x % mod;
		x = x * x % mod;
		n = n >> 1;
	}
	return ans;
}
void setcomb() {
	fac[0] = 1;
	ifac[0] = 1;
	for (ll i = 0; i < 2000010; i++) {
		fac[i + 1] = fac[i] * (i + 1) % M; // n!(mod M)
	}
	ifac[2000010] = mpow(fac[2000010], M - 2);
	for (ll i = 2000010; i > 0; i--) {
		ifac[i - 1] = ifac[i] * i%M;
	}
}
ll comb(ll a, ll b) {
	if (a == 0 && b == 0)return 1;
	if (a < b || a < 0)return 0;
	ll tmp = ifac[a - b] * ifac[b] % M;
	return tmp * fac[a] % M;
}
ll perm(ll a, ll b) {
	if (a == 0 && b == 0)return 1;
	if (a < b || a < 0)return 0;
	return fac[a] * ifac[a - b] % M;
}
long long modinv(long long a) {
	long long b = M, u = 1, v = 0;
	while (b) {
		long long t = a / b;
		a -= t * b; swap(a, b);
		u -= t * v; swap(u, v);
	}
	u %= M;
	if (u < 0) u += M;
	return u;
}
vector<vector<ll>> mul(vector<vector<ll>> a, vector<vector<ll>> b, int n) {
	int i, j, k, t;
	vector<vector<ll>> c(n);
	for (i = 0; i < n; i++) {
		for (j = 0; j < n; j++) {
			t = 0;
			for (k = 0; k < n; k++)
				t = (t + a[i][k] * b[k][j] % M) % M;
			c[i].push_back(t);
		}
	}
	return c;
}

template< typename Monoid >
struct SegmentTree {
	using F = function< Monoid(Monoid, Monoid) >;

	int sz;
	vector< Monoid > seg;

	const F f;
	const Monoid M1;

	SegmentTree(int n, const F f, const Monoid &M1) : f(f), M1(M1) {
		sz = 1;
		while (sz < n) sz <<= 1;
		seg.assign(2 * sz, M1);
	}

	void set(int k, const Monoid &x) {
		seg[k + sz] = x;
	}

	void build() {
		for (int k = sz - 1; k > 0; k--) {
			seg[k] = f(seg[2 * k + 0], seg[2 * k + 1]);
		}
	}

	void update(int k, const Monoid &x) {
		k += sz;
		seg[k] = x;
		while (k >>= 1) {
			seg[k] = f(seg[2 * k + 0], seg[2 * k + 1]);
		}
	}

	Monoid query(int a, int b) {
		Monoid L = M1, R = M1;
		for (a += sz, b += sz; a < b; a >>= 1, b >>= 1) {
			if (a & 1) L = f(L, seg[a++]);
			if (b & 1) R = f(seg[--b], R);
		}
		return f(L, R);
	}

	Monoid operator[](const int &k) const {
		return seg[k + sz];
	}

	template< typename C >
	int find_subtree(int a, const C &check, Monoid &M, bool type) {
		while (a < sz) {
			Monoid nxt = type ? f(seg[2 * a + type], M) : f(M, seg[2 * a + type]);
			if (check(nxt)) a = 2 * a + type;
			else M = nxt, a = 2 * a + 1 - type;
		}
		return a - sz;
	}


	template< typename C >
	int find_first(int a, const C &check) {
		Monoid L = M1;
		if (a <= 0) {
			if (check(f(L, seg[1]))) return find_subtree(1, check, L, false);
			return -1;
		}
		int b = sz;
		for (a += sz, b += sz; a < b; a >>= 1, b >>= 1) {
			if (a & 1) {
				Monoid nxt = f(L, seg[a]);
				if (check(nxt)) return find_subtree(a, check, L, false);
				L = nxt;
				++a;
			}
		}
		return -1;
	}

	template< typename C >
	int find_last(int b, const C &check) {
		Monoid R = M1;
		if (b >= sz) {
			if (check(f(seg[1], R))) return find_subtree(1, check, R, true);
			return -1;
		}
		int a = sz;
		for (b += sz; a < b; a >>= 1, b >>= 1) {
			if (b & 1) {
				Monoid nxt = f(seg[--b], R);
				if (check(nxt)) return find_subtree(b, check, R, true);
				R = nxt;
			}
		}
		return -1;
	}
};

template< unsigned mod >
struct RollingHash {
	vector< unsigned > hashed, power;

	inline unsigned mul(unsigned a, unsigned b) const {
		unsigned long long x = (unsigned long long) a * b;
		unsigned xh = (unsigned)(x >> 32), xl = (unsigned)x, d, m;
		asm("divl %4; \n\t" : "=a" (d), "=d" (m) : "d" (xh), "a" (xl), "r" (mod));
		return m;
	}

	RollingHash(const string &s, unsigned base = 10007) {
		int sz = (int)s.size();
		hashed.assign(sz + 1, 0);
		power.assign(sz + 1, 0);
		power[0] = 1;
		for (int i = 0; i < sz; i++) {
			power[i + 1] = mul(power[i], base);
			hashed[i + 1] = mul(hashed[i], base) + s[i];
			if (hashed[i + 1] >= mod) hashed[i + 1] -= mod;
		}
	}

	unsigned get(int l, int r) const {
		unsigned ret = hashed[r] + mod - mul(hashed[l], power[r - l]);
		if (ret >= mod) ret -= mod;
		return ret;
	}

	unsigned connect(unsigned h1, int h2, int h2len) const {
		unsigned ret = mul(h1, power[h2len]) + h2;
		if (ret >= mod) ret -= mod;
		return ret;
	}

	int LCP(const RollingHash< mod > &b, int l1, int r1, int l2, int r2) {
		int len = min(r1 - l1, r2 - l2);
		int low = -1, high = len + 1;
		while (high - low > 1) {
			int mid = (low + high) / 2;
			if (get(l1, l1 + mid) == b.get(l2, l2 + mid)) low = mid;
			else high = mid;
		}
		return (low);
	}
};

using RH = RollingHash< 1000000007 >;

template< typename T >
struct edge {
	int src, to;
	T cost;

	edge(int to, T cost) : src(-1), to(to), cost(cost) {}

	edge(int src, int to, T cost) : src(src), to(to), cost(cost) {}

	edge &operator=(const int &x) {
		to = x;
		return *this;
	}

	operator int() const { return to; }
};

template< typename T >
using Edges = vector< edge< T > >;
template< typename T >
using WeightedGraph = vector< Edges< T > >;
using UnWeightedGraph = vector< vector< int > >;
template< typename T >
using Matrix = vector< vector< T > >;

template< typename G >
struct DoublingLowestCommonAncestor {
	const int LOG;
	vector< int > dep;
	const G &g;
	vector< vector< int > > table;

	DoublingLowestCommonAncestor(const G &g) : g(g), dep(g.size()), LOG(32 - __builtin_clz(g.size())) {
		table.assign(LOG, vector< int >(g.size(), -1));
	}

	void dfs(int idx, int par, int d) {
		table[0][idx] = par;
		dep[idx] = d;
		for (auto &to : g[idx]) {
			if (to != par) dfs(to, idx, d + 1);
		}
	}

	void build() {
		dfs(0, -1, 0);
		for (int k = 0; k + 1 < LOG; k++) {
			for (int i = 0; i < table[k].size(); i++) {
				if (table[k][i] == -1) table[k + 1][i] = -1;
				else table[k + 1][i] = table[k][table[k][i]];
			}
		}
	}

	int query(int u, int v) {
		if (dep[u] > dep[v]) swap(u, v);
		for (int i = LOG - 1; i >= 0; i--) {
			if (((dep[v] - dep[u]) >> i) & 1) v = table[i][v];
		}
		if (u == v) return u;
		for (int i = LOG - 1; i >= 0; i--) {
			if (table[i][u] != table[i][v]) {
				u = table[i][u];
				v = table[i][v];
			}
		}
		return table[0][u];
	}
};

using Real = double;
using Point = complex< Real >;
const Real EPS = 1e-8, PI = acos(-1);

inline bool eq(Real a, Real b) { return fabs(b - a) < EPS; }

Point operator*(const Point &p, const Real &d) {
	return Point(real(p) * d, imag(p) * d);
}

istream &operator>>(istream &is, Point &p) {
	Real a, b;
	is >> a >> b;
	p = Point(a, b);
	return is;
}

ostream &operator<<(ostream &os, Point &p) {
	return os << fixed << setprecision(10) << p.real() << " " << p.imag();
}

// 点 p を反時計回りに theta 回転
Point rotate(Real theta, const Point &p) {
	return Point(cos(theta) * p.real() - sin(theta) * p.imag(), sin(theta) * p.real() + cos(theta) * p.imag());
}

Real radian_to_degree(Real r) {
	return (r * 180.0 / PI);
}

Real degree_to_radian(Real d) {
	return (d * PI / 180.0);
}

// a-b-c の角度のうち小さい方を返す
Real get_angle(const Point &a, const Point &b, const Point &c) {
	const Point v(b - a), w(c - b);
	Real alpha = atan2(v.imag(), v.real()), beta = atan2(w.imag(), w.real());
	if (alpha > beta) swap(alpha, beta);
	Real theta = (beta - alpha);
	return min(theta, 2 * acos(-1) - theta);
}

namespace std {
	bool operator<(const Point &a, const Point &b) {
		return a.real() != b.real() ? a.real() < b.real() : a.imag() < b.imag();
	}
}


struct Line {
	Point a, b;

	Line() = default;

	Line(Point a, Point b) : a(a), b(b) {}

	Line(Real A, Real B, Real C) // Ax + By = C
	{
		if (eq(A, 0)) a = Point(0, C / B), b = Point(1, C / B);
		else if (eq(B, 0)) b = Point(C / A, 0), b = Point(C / A, 1);
		else a = Point(0, C / B), b = Point(C / A, 0);
	}

	friend ostream &operator<<(ostream &os, Line &p) {
		return os << p.a << " to " << p.b;
	}

	friend istream &operator>>(istream &is, Line &a) {
		return is >> a.a >> a.b;
	}
};

struct Segment : Line {
	Segment() = default;

	Segment(Point a, Point b) : Line(a, b) {}
};

struct Circle {
	Point p;
	Real r;

	Circle() = default;

	Circle(Point p, Real r) : p(p), r(r) {}
};

using Points = vector< Point >;
using Polygon = vector< Point >;
using Segments = vector< Segment >;
using Lines = vector< Line >;
using Circles = vector< Circle >;

Real distance(const Point &a, const Point &b) {
	return abs(a - b);
}

// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_7_E
pair< Point, Point > crosspoint(const Circle &c1, const Circle &c2) {
	Real d = abs(c1.p - c2.p);
	Real a = acos((c1.r * c1.r + d * d - c2.r * c2.r) / (2 * c1.r * d));
	Real t = atan2(c2.p.imag() - c1.p.imag(), c2.p.real() - c1.p.real());
	Point p1 = c1.p + Point(cos(t + a) * c1.r, sin(t + a) * c1.r);
	Point p2 = c1.p + Point(cos(t - a) * c1.r, sin(t - a) * c1.r);
	return { p1, p2 };
}

int main() {
	int n, k, i, j;
	double x[66], y[66], c[66];
	cin >> n >> k;
	for (i = 0; i < n; i++)
		cin >> x[i] >> y[i] >> c[i];
	double ok = 150000, ng = 0;
	while (ok - ng > 1e-8) {
		double ce = (ok + ng) / 2.0;
		Circles v;
		for (i = 0; i < n; i++)
			v.pb(Circle(complex<double>(x[i], y[i]), ce / c[i]));
		Points p;
		for (i = 0; i < n; i++) {
          p.pb(v[i].p);
			for (j = i + 1; j < n; j++) {
				if (distance(v[i].p, v[j].p) < v[i].r + v[j].r - 1e-8) {
					p.pb(crosspoint(v[i], v[j]).first);
					p.pb(crosspoint(v[i], v[j]).second);
				}
			}
		}
		int flag = 0;
		for (auto &e : p) {
			int count = 0;
			for (i = 0; i < n; i++)
				if (distance(e, v[i].p) < v[i].r + 1e-8)
					count++;
			if (count >= k)
				flag = 1;
		}
		if (flag)
			ok = ce;
		else
			ng = ce;
	}
	cout << setprecision(10) << ok << endl;
}


Measured memory_bytes: 31684