#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int INF = 1e9;
const ll LINF = 1e18;
inline ll gcd(ll a, ll b) { return b ? gcd(b, a%b) : a; }
inline ll lcm(ll a, ll b) { return a / gcd(a, b)*b; }
template<class S,class T> ostream& operator << (ostream& out,const pair<S,T>& o){ out << "(" << o.first << "," << o.second << ")"; return out; }
template<class T> ostream& operator << (ostream& out,const vector<T>& V){ for(int i = 0; i < V.size(); i++){ out << V[i]; if(i!=V.size()-1) out << " ";} return out; }
template<class T> ostream& operator << (ostream& out,const vector<vector<T> >& Mat){ for(int i = 0; i < Mat.size(); i++) { if(i != 0) out << endl; out << Mat[i];} return out; }
template<class S,class T> ostream& operator << (ostream& out,const map<S,T>& mp){ out << "{ "; for(auto it = mp.begin(); it != mp.end(); it++){ out << it->first << ":" << it->second; if(mp.size()-1 != distance(mp.begin(),it)) out << ", "; } out << " }"; return out; }
template<typename T>vector<T> make_v(size_t a){return vector<T>(a);}
template<typename T,typename... Ts>auto make_v(size_t a,Ts... ts){return vector<decltype(make_v<T>(ts...))>(a,make_v<T>(ts...));}
template<typename T,typename V> typename enable_if<is_class<T>::value==0>::type fill_v(T &t,const V &v){t=v;}
template<typename T,typename V> typename enable_if<is_class<T>::value!=0>::type fill_v(T &t,const V &v){for(auto &e:t) fill_v(e,v);}
/*
 <url:https://atcoder.jp/contests/abc157/tasks/abc157_f>
 問題文============================================================
 F - Yakiniku Optimization Problem
 =================================================================
 解説=============================================================
 
 ================================================================
 */

typedef long double ld;
typedef complex<ld> Point;
const ld eps = 1e-9, pi = acos(-1.0);
namespace std {
    bool operator<(const Point &lhs, const Point &rhs) {
        if (lhs.real() < rhs.real() - eps) return true;
        if (lhs.real() > rhs.real() + eps) return false;
        return lhs.imag() < rhs.imag();
    }
}
Point input_point() { ld x, y; cin >> x >> y; return Point(x, y); } // 点の入力
bool eq(ld a, ld b) { return (abs(a - b) < eps); } // 誤差つき等号判定
ld dot(Point a, Point b) { return real(conj(a) * b); } // 内積
ld cross(Point a, Point b) { return imag(conj(a) * b); } // 外積

// 直線の定義
class Line {
public:
    Point a, b;
    Line() : a(Point(0, 0)), b(Point(0, 0)) {}
    Line(Point a, Point b) : a(a), b(b) {}
    Point operator[](const int _num) {
        if (_num == 0)return a;
        else if (_num == 1)return b;
        else assert(false);
    }
};

// 円の定義
class Circle {
public:
    Point p;
    ld r;
    Circle() : p(Point(0, 0)), r(0) {}
    Circle(Point p, ld r) : p(p), r(r) {}
};

// 垂線の足
Point proj(Line l, Point p) {
    ld t = dot(p - l.a, l.a - l.b) / norm(l.a - l.b);
    return l.a + t * (l.a - l.b);
}

// CCW
int ccw(Point a, Point b, Point c) {
    b -= a; c -= a;
    if (cross(b, c) > eps) return 1;   // a,b,cが反時計周りの順に並ぶ
    if (cross(b, c) < -eps) return -1; // a,b,cが時計周りの順に並ぶ
    if (dot(b, c) < 0) return 2;       // c,a,bの順に直線に並ぶ
    if (norm(b) < norm(c)) return -2;  // a,b,cの順に直線に並ぶ
    return 0;                          // a,c,bの順に直線に並ぶ
}

/* 交差判定 */
// 直線と直線の交差判定
bool isis_ll(Line l, Line m) { return !eq(cross(l.b - l.a, m.b - m.a), 0); }
// 直線と線分の交差判定
bool isis_ls(Line l, Line s) {
    return isis_ll(l, s) &&
        (cross(l.b - l.a, s.a - l.a) * cross(l.b - l.a, s.b - l.a) < eps);
}
// 線分と線分の交差判定
bool isis_ss(Line s, Line t) {
    return ccw(s.a, s.b, t.a) * ccw(s.a, s.b, t.b) <= 0 &&
        ccw(t.a, t.b, s.a) * ccw(t.a, t.b, s.b) <= 0;
}
// 点の直線上判定
bool isis_lp(Line l, Point p) { return (abs(cross(l.b - p, l.a - p)) < eps); }
// 点の線分上判定
bool isis_sp(Line s, Point p) { return (abs(s.a - p) + abs(s.b - p) - abs(s.b - s.a) < eps); }

/* 距離 */
// 直線と直線の交点
Point is_ll(Line s, Line t) {
    Point sv = s.b - s.a, tv = t.b - t.a;
    assert(cross(sv, tv) != 0);
    return s.a + sv * cross(tv, t.a - s.a) / cross(tv, sv);
}

// 直線と点の距離
ld dist_lp(Line l, Point p) {
    return abs(p - proj(l, p));
}

// 直線と直線の距離
ld dist_ll(Line l, Line m) {
    return isis_ll(l, m) ? 0 : dist_lp(l, m.a);
}

// 直線と線分の距離
ld dist_ls(Line l, Line s) {
    return isis_ls(l, s) ? 0 : min(dist_lp(l, s.a), dist_lp(l, s.b));
}

// 線分と点の距離
ld dist_sp(Line s, Point p) {
    Point r = proj(s, p);
    return isis_sp(s, r) ? abs(r - p) : min(abs(s.a - p), abs(s.b - p));
}

// 線分と線分の距離
ld dist_ss(Line s, Line t) {
    if (isis_ss(s, t)) return 0;
    return min({ dist_sp(s, t.a), dist_sp(s, t.b), dist_sp(t, s.a), dist_sp(t, s.b) });
}

/* 円 */
// 円と円の交点
vector<Point> is_cc(Circle c1, Circle c2) {
    vector<Point> res;
    ld d = abs(c1.p - c2.p);
    ld rc = (d * d + c1.r * c1.r - c2.r * c2.r) / (2 * d);
    ld dfr = c1.r * c1.r - rc * rc;
    if (abs(dfr) < eps) dfr = 0.0;
    else if (dfr < 0.0) return res; // no intersection
    ld rs = sqrt(dfr);
    Point diff = (c2.p - c1.p) / d;
    res.push_back(c1.p + diff * Point(rc, rs));
    if (dfr != 0.0) res.push_back(c1.p + diff * Point(rc, -rs));
    return res;
}

template<class Type>
Type solve(Type res = Type()){
    int N,K; cin >> N >> K;
    
    vector<Point> ps(N);
    vector<double> cs(N);
    for(int i = 0; i < N;i++){
        ps[i] = input_point();
        cin >> cs[i];
    }
    
    double lt = 0, rt = 500000;
    
    auto ok = [&](double t){
        vector<Circle> Cs;
        for(int i = 0; i < N;i++) Cs.emplace_back(ps[i],t/cs[i]);
        
        // pattern 1
        for(int i = 0; i < N;i++){
            int num = 0;
            for(int j = 0; j < N;j++){
                if(abs(Cs[i].p - Cs[j].p) < Cs[j].r
                   + eps){
                    num++;
                }
            }
            if(num >= K) return true;
        }
        
        // pattern 2
        for(int i = 0; i < N;i++){
            for(int j = 0; j < N;j++){
                auto cc = is_cc(Cs[i],Cs[j]);
                for(auto c:cc){
                    
                    int num = 0;
                    for(int k = 0; k < N;k++){
                        if(abs(c-Cs[k].p) < Cs[k].r + eps){
                            num++;
                        }
                    }
                    if(num >= K) return true;
                }
            }
        }
        return false;
    };
    for(int unchi = 0; unchi < 100; unchi++){
        double t = (lt + rt)/2;
        
        if(ok(t)) rt = t;
        else lt = t;
    }
    res = lt;
    return res;
}
int main(void) {
    cin.tie(0); ios_base::sync_with_stdio(false);
    // solve(0);
    cout << fixed << setprecision(15) << solve<double>() << endl;
    return 0;
}


Measured memory_bytes: 384