#include <iostream>
#include<queue>
#include<stack>
#include<vector>
#include<set>
#include<map>
#include<algorithm>
#include<cstring>
#include<string>
#include<cassert>
#include<cmath>
#include<climits>
#include<iomanip>
#include<bitset>
#include<unordered_map>

using namespace std;

#define REP(i,n) for(ll (i)=0;(i)<(n);(i)++)
#define rep(i,j,n) for(ll (i)=(j);(i)<(n);(i)++)
#define FOR(i,c) for(decltype((c).begin())i=(c).begin();i!=(c).end();++i)
#define ll long long
#define ull unsigned long long
#define all(hoge) (hoge).begin(),(hoge).end()
#define en '\n'
typedef pair<ll, ll> P;
const long long INF = 1LL << 60;
const int INF_INT = 1 << 25;
const long long MOD = 1e9 + 7;
typedef vector<ll> Array;
typedef vector<Array> Matrix;
template <class T> using vec = vector<T>;
template <class T> using vvec = vector<vec<T>>;
const int loose = 0;
const int tight = 1;

template<class T> inline bool chmin(T& a, T b) {
	if (a > b) {
		a = b;
		return true;
	}
	return false;
}
template<class T> inline bool chmax(T& a, T b) {
	if (a < b) {
		a = b;
		return true;
	}
	return false;
}

//グラフ関連
struct Edge {//グラフ
	ll to, cap, rev;
	Edge(ll _to, ll _cap, ll _rev) {
		to = _to; cap = _cap; rev = _rev;
	}
};
typedef vector<Edge> Edges;
typedef vector<Edges> Graph;

void add_edge(Graph& G, ll from, ll to, ll cap, bool revFlag, ll revCap) {
	G[from].push_back(Edge(to, cap, (ll)G[to].size()));
	if (revFlag)G[to].push_back(Edge(from, revCap, (ll)G[from].size() - 1));
}


//幾何ライブラリ
using DD = long double;
const DD EPS = 1e-8;//許容誤差
const DD PI = acosl(-1.0);
DD torad(int deg) { return (DD)(deg)*PI / 180; }
DD todeg(DD ang) { return ang * 180 / PI; }

DD dis(pair<DD, DD> a, pair<DD, DD> b) {
	return  sqrt((a.first - b.first) * (a.first - b.first) + (a.second - b.second) * (a.second - b.second));
}

/* Point */
struct Point {
    DD x, y;
    Point(DD x = 0.0, DD y = 0.0) : x(x), y(y) {}
    friend ostream& operator << (ostream &s, const Point &p) {return s << '(' << p.x << ", " << p.y << ')';}
};
inline Point operator + (const Point &p, const Point &q) {return Point(p.x + q.x, p.y + q.y);}
inline Point operator - (const Point &p, const Point &q) {return Point(p.x - q.x, p.y - q.y);}
inline Point operator * (const Point &p, DD a) {return Point(p.x * a, p.y * a);}
inline Point operator * (DD a, const Point &p) {return Point(a * p.x, a * p.y);}
inline Point operator * (const Point &p, const Point &q) {return Point(p.x * q.x - p.y * q.y, p.x * q.y + p.y * q.x);}
inline Point operator / (const Point &p, DD a) {return Point(p.x / a, p.y / a);}
inline Point conj(const Point &p) {return Point(p.x, -p.y);}
inline Point rot(const Point &p, DD ang) {return Point(cos(ang) * p.x - sin(ang) * p.y, sin(ang) * p.x + cos(ang) * p.y);}
inline Point rot90(const Point &p) {return Point(-p.y, p.x);}
inline DD cross(const Point &p, const Point &q) {return p.x * q.y - p.y * q.x;}
inline DD dot(const Point &p, const Point &q) {return p.x * q.x + p.y * q.y;}
inline DD norm(const Point &p) {return dot(p, p);}
inline DD abs(const Point &p) {return sqrt(dot(p, p));}
inline DD amp(const Point &p) {DD res = atan2(p.y, p.x); if (res < 0) res += PI*2; return res;}
inline bool eq(const Point &p, const Point &q) {return abs(p - q) < EPS;}
inline bool operator < (const Point &p, const Point &q) {return (abs(p.x - q.x) > EPS ? p.x < q.x : p.y < q.y);}
inline bool operator > (const Point &p, const Point &q) {return (abs(p.x - q.x) > EPS ? p.x > q.x : p.y > q.y);}
inline Point operator / (const Point &p, const Point &q) {return p * conj(q) / norm(q);}

/* Line */
struct Line : vector<Point> {
    Line(Point a = Point(0.0, 0.0), Point b = Point(0.0, 0.0)) {
        this->push_back(a);
        this->push_back(b);
    }
    friend ostream& operator << (ostream &s, const Line &l) {return s << '{' << l[0] << ", " << l[1] << '}';}
};

/* Circle */
struct Circle : Point {
    DD r;
    Circle(Point p = Point(0.0, 0.0), DD r = 0.0) : Point(p), r(r) {}
    friend ostream& operator << (ostream &s, const Circle &c) {return s << '(' << c.x << ", " << c.y << ", " << c.r << ')';}
};

// 円の交点
vector<Point> crosspoint(const Circle &e, const Circle &f) {
    vector<Point> res;
    DD d = abs(e - f);
    if (d < EPS) return vector<Point>();
    if (d > e.r + f.r + EPS) return vector<Point>();
    if (d < abs(e.r - f.r) - EPS) return vector<Point>();
    DD rcos = (d * d + e.r * e.r - f.r * f.r) / (2.0 * d), rsin;
    if (e.r - abs(rcos) < EPS) rsin = 0;
    else rsin = sqrt(e.r * e.r - rcos * rcos);
    Point dir = (f - e) / d;
    Point p1 = e + dir * Point(rcos, rsin);
    Point p2 = e + dir * Point(rcos, -rsin);
    res.push_back(p1);
    if (!eq(p1, p2)) res.push_back(p2);
    return res;
}
int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);

	ll n, k;
	cin >> n >> k;
	vector<DD> x(n), y(n), c(n);
	REP(i, n) cin >> x[i] >> y[i] >> c[i];

	auto num = [&](pair<DD, DD> xy, DD t) {
		int res = 0;
		REP(i, n) {
			if (dis(xy, { x[i],y[i] }) <= t / c[i] + EPS) res++;
		}
		return res;
	};

	auto check = [&](DD t)->ll {
		REP(i, n) {
			Circle a(Point(x[i], y[i]), t / c[i]);
			if (num({a.x,a.y}, t) >= k) return true;//円の中心
			rep(j, i + 1, n) {
				Circle b(Point(x[j], y[j]), t / c[j]);
				vector<Point> cp = crosspoint(a, b);//円の交点
				for (auto p : cp) {
					if (num({p.x,p.y}, t) >= k) return true;
				}
			}
		}
		return false;
	};

	DD l = 0;
	DD r = 1000000;//4000*100よりは小さい
	while (r - l > EPS) {
		DD mid = (l + r) / 2.0;
		if (check(mid)) r = mid;
		else l = mid;
	}

	cout << fixed << setprecision(8)<< r << endl;

	return 0;
}

Measured memory_bytes: 384