// Slower C++ solution:
#include<bits/stdc++.h>

using namespace std;

using ll=long long;

#define fr(i,n) for(int i=0;i<(n);++i)

#define Fr(i,n) for(int i=1;i<=(n);++i)

#define ifr(i,n) for(int i=(n)-1;i>=0;--i)

#define iFr(i,n) for(int i=(n);i>0;--i)



using Real = double;

using Point = complex< Real >;

const Real EPS = 1e-10, 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 cross(const Point &a, const Point &b) {

    return real(a) * imag(b) - imag(a) * real(b);

}



Real dot(const Point &a, const Point &b) {

    return real(a) * real(b) + imag(a) * imag(b);

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_1_C

// 点の回転方向

int ccw(const Point &a, Point b, Point c) {

    b = b - a, c = c - a;

    if(cross(b, c) > EPS) return +1;  // "COUNTER_CLOCKWISE"

    if(cross(b, c) < -EPS) return -1; // "CLOCKWISE"

    if(dot(b, c) < 0) return +2;      // "ONLINE_BACK"

    if(norm(b) < norm(c)) return -2;  // "ONLINE_FRONT"

    return 0;                         // "ON_SEGMENT"

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_2_A

// 平行判定

bool parallel(const Line &a, const Line &b) {

    return eq(cross(a.b - a.a, b.b - b.a), 0.0);

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_2_A

// 垂直判定

bool orthogonal(const Line &a, const Line &b) {

    return eq(dot(a.a - a.b, b.a - b.b), 0.0);

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_1_A

// 射影

// 直線 l に p から垂線を引いた交点を求める

Point projection(const Line &l, const Point &p) {

    double t = dot(p - l.a, l.a - l.b) / norm(l.a - l.b);

    return l.a + (l.a - l.b) * t;

}



Point projection(const Segment &l, const Point &p) {

    double t = dot(p - l.a, l.a - l.b) / norm(l.a - l.b);

    return l.a + (l.a - l.b) * t;

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_1_B

// 反射

// 直線 l を対称軸として点 p  と線対称にある点を求める

Point reflection(const Line &l, const Point &p) {

    return p + (projection(l, p) - p) * 2.0;

}



bool intersect(const Line &l, const Point &p) {

    return abs(ccw(l.a, l.b, p)) != 1;

}



bool intersect(const Line &l, const Line &m) {

    return abs(cross(l.b - l.a, m.b - m.a)) > EPS || abs(cross(l.b - l.a, m.b - l.a)) < EPS;

}



bool intersect(const Segment &s, const Point &p) {

    return ccw(s.a, s.b, p) == 0;

}



bool intersect(const Line &l, const Segment &s) {

    return cross(l.b - l.a, s.a - l.a) * cross(l.b - l.a, s.b - l.a) < EPS;

}



Real distance(const Line &l, const Point &p);



bool intersect(const Circle &c, const Line &l) {

    return distance(l, c.p) <= c.r + EPS;

}



bool intersect(const Circle &c, const Point &p) {

    return abs(abs(p - c.p) - c.r) < EPS;

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_2_B

bool intersect(const Segment &s, const Segment &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;

}



int intersect(const Circle &c, const Segment &l) {

    if(norm(projection(l, c.p) - c.p) - c.r * c.r > EPS) return 0;

    auto d1 = abs(c.p - l.a), d2 = abs(c.p - l.b);

    if(d1 < c.r + EPS && d2 < c.r + EPS) return 0;

    if(d1 < c.r - EPS && d2 > c.r + EPS || d1 > c.r + EPS && d2 < c.r - EPS) return 1;

    const Point h = projection(l, c.p);

    if(dot(l.a - h, l.b - h) < 0) return 2;

    return 0;

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_7_A&lang=jp

int intersect(Circle c1, Circle c2) {

    if(c1.r < c2.r) swap(c1, c2);

    Real d = abs(c1.p - c2.p);

    if(c1.r + c2.r < d) return 4;

    if(eq(c1.r + c2.r, d)) return 3;

    if(c1.r - c2.r < d) return 2;

    if(eq(c1.r - c2.r, d)) return 1;

    return 0;

}



Real distance(const Point &a, const Point &b) {

    return abs(a - b);

}



Real distance(const Line &l, const Point &p) {

    return abs(p - projection(l, p));

}



Real distance(const Line &l, const Line &m) {

    return intersect(l, m) ? 0 : distance(l, m.a);

}



Real distance(const Segment &s, const Point &p) {

    Point r = projection(s, p);

    if(intersect(s, r)) return abs(r - p);

    return min(abs(s.a - p), abs(s.b - p));

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_2_D

Real distance(const Segment &a, const Segment &b) {

    if(intersect(a, b)) return 0;

    return min({distance(a, b.a), distance(a, b.b), distance(b, a.a), distance(b, a.b)});

}



Real distance(const Line &l, const Segment &s) {

    if(intersect(l, s)) return 0;

    return min(distance(l, s.a), distance(l, s.b));

}



Point crosspoint(const Line &l, const Line &m) {

    Real A = cross(l.b - l.a, m.b - m.a);

    Real B = cross(l.b - l.a, l.b - m.a);

    if(eq(abs(A), 0.0) && eq(abs(B), 0.0)) return m.a;

    return m.a + (m.b - m.a) * B / A;

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_2_C

Point crosspoint(const Segment &l, const Segment &m) {

    return crosspoint(Line(l), Line(m));

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_7_D

pair< Point, Point > crosspoint(const Circle &c, const Line l) {

    Point pr = projection(l, c.p);

    Point e = (l.b - l.a) / abs(l.b - l.a);

    if(eq(distance(l, c.p), c.r)) return {pr, pr};

    double base = sqrt(c.r * c.r - norm(pr - c.p));

    return {pr - e * base, pr + e * base};

}



pair< Point, Point > crosspoint(const Circle &c, const Segment &l) {

    Line aa = Line(l.a, l.b);

    if(intersect(c, l) == 2) return crosspoint(c, aa);

    auto ret = crosspoint(c, aa);

    if(dot(l.a - ret.first, l.b - ret.first) < 0) ret.second = ret.first;

    else ret.first = ret.second;

    return ret;

}



// 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};

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_7_F

// 点 p を通る円 c の接線

pair< Point, Point > tangent(const Circle &c1, const Point &p2) {

    return crosspoint(c1, Circle(p2, sqrt(norm(c1.p - p2) - c1.r * c1.r)));

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_7_G

// 円 c1, c2 の共通接線

Lines tangent(Circle c1, Circle c2) {

    Lines ret;

    if(c1.r < c2.r) swap(c1, c2);

    Real g = norm(c1.p - c2.p);

    if(eq(g, 0)) return ret;

    Point u = (c2.p - c1.p) / sqrt(g);

    Point v = rotate(PI * 0.5, u);

    for(int s : {-1, 1}) {

        Real h = (c1.r + s * c2.r) / sqrt(g);

        if(eq(1 - h * h, 0)) {

            ret.emplace_back(c1.p + u * c1.r, c1.p + (u + v) * c1.r);

        } else if(1 - h * h > 0) {

            Point uu = u * h, vv = v * sqrt(1 - h * h);

            ret.emplace_back(c1.p + (uu + vv) * c1.r, c2.p - (uu + vv) * c2.r * s);

            ret.emplace_back(c1.p + (uu - vv) * c1.r, c2.p - (uu - vv) * c2.r * s);

        }

    }

    return ret;

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_3_B

// 凸性判定

bool is_convex(const Polygon &p) {

    int n = (int) p.size();

    for(int i = 0; i < n; i++) {

        if(ccw(p[(i + n - 1) % n], p[i], p[(i + 1) % n]) == -1) return false;

    }

    return true;

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_4_A

// 凸包

Polygon convex_hull(Polygon &p) {

    int n = (int) p.size(), k = 0;

    if(n <= 2) return p;

    sort(p.begin(), p.end());

    vector< Point > ch(2 * n);

    for(int i = 0; i < n; ch[k++] = p[i++]) {

        while(k >= 2 && cross(ch[k - 1] - ch[k - 2], p[i] - ch[k - 1]) < EPS) --k;

    }

    for(int i = n - 2, t = k + 1; i >= 0; ch[k++] = p[i--]) {

        while(k >= t && cross(ch[k - 1] - ch[k - 2], p[i] - ch[k - 1]) < EPS) --k;

    }

    ch.resize(k - 1);

    return ch;

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_3_C

// 多角形と点の包含判定

enum {

    OUT, ON, IN

};



int contains(const Polygon &Q, const Point &p) {

    bool in = false;

    for(int i = 0; i < Q.size(); i++) {

        Point a = Q[i] - p, b = Q[(i + 1) % Q.size()] - p;

        if(a.imag() > b.imag()) swap(a, b);

        if(a.imag() <= 0 && 0 < b.imag() && cross(a, b) < 0) in = !in;

        if(cross(a, b) == 0 && dot(a, b) <= 0) return ON;

    }

    return in ? IN : OUT;

}





// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=1033

// 線分の重複除去

void merge_segments(vector< Segment > &segs) {



    auto merge_if_able = [](Segment &s1, const Segment &s2) {

        if(abs(cross(s1.b - s1.a, s2.b - s2.a)) > EPS) return false;

        if(ccw(s1.a, s2.a, s1.b) == 1 || ccw(s1.a, s2.a, s1.b) == -1) return false;

        if(ccw(s1.a, s1.b, s2.a) == -2 || ccw(s2.a, s2.b, s1.a) == -2) return false;

        s1 = Segment(min(s1.a, s2.a), max(s1.b, s2.b));

        return true;

    };



    for(int i = 0; i < segs.size(); i++) {

        if(segs[i].b < segs[i].a) swap(segs[i].a, segs[i].b);

    }

    for(int i = 0; i < segs.size(); i++) {

        for(int j = i + 1; j < segs.size(); j++) {

            if(merge_if_able(segs[i], segs[j])) {

                segs[j--] = segs.back(), segs.pop_back();

            }

        }

    }

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=1033

// 線分アレンジメント

// 任意の2線分の交点を頂点としたグラフを構築する

vector< vector< int > > segment_arrangement(vector< Segment > &segs, vector< Point > &ps) {

    vector< vector< int > > g;

    int N = (int) segs.size();

    for(int i = 0; i < N; i++) {

        ps.emplace_back(segs[i].a);

        ps.emplace_back(segs[i].b);

        for(int j = i + 1; j < N; j++) {

            const Point p1 = segs[i].b - segs[i].a;

            const Point p2 = segs[j].b - segs[j].a;

            if(cross(p1, p2) == 0) continue;

            if(intersect(segs[i], segs[j])) {

                ps.emplace_back(crosspoint(segs[i], segs[j]));

            }

        }

    }

    sort(begin(ps), end(ps));

    ps.erase(unique(begin(ps), end(ps)), end(ps));



    int M = (int) ps.size();

    g.resize(M);

    for(int i = 0; i < N; i++) {

        vector< int > vec;

        for(int j = 0; j < M; j++) {

            if(intersect(segs[i], ps[j])) {

                vec.emplace_back(j);

            }

        }

        for(int j = 1; j < vec.size(); j++) {

            g[vec[j - 1]].push_back(vec[j]);

            g[vec[j]].push_back(vec[j - 1]);

        }

    }

    return (g);

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_4_C

// 凸多角形の切断

// 直線 l.a-l.b で切断しその左側にできる凸多角形を返す

Polygon convex_cut(const Polygon &U, Line l) {

    Polygon ret;

    for(int i = 0; i < U.size(); i++) {

        Point now = U[i], nxt = U[(i + 1) % U.size()];

        if(ccw(l.a, l.b, now) != -1) ret.push_back(now);

        if(ccw(l.a, l.b, now) * ccw(l.a, l.b, nxt) < 0) {

            ret.push_back(crosspoint(Line(now, nxt), l));

        }

    }

    return (ret);

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_3_A

// 多角形の面積

Real area(const Polygon &p) {

    Real A = 0;

    for(int i = 0; i < p.size(); ++i) {

        A += cross(p[i], p[(i + 1) % p.size()]);

    }

    return A * 0.5;

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_7_H

// 円と多角形の共通部分の面積

Real area(const Polygon &p, const Circle &c) {

    if(p.size() < 3) return 0.0;

    function< Real(Circle, Point, Point) > cross_area = [&](const Circle &c, const Point &a, const Point &b) {

        Point va = c.p - a, vb = c.p - b;

        Real f = cross(va, vb), ret = 0.0;

        if(eq(f, 0.0)) return ret;

        if(max(abs(va), abs(vb)) < c.r + EPS) return f;

        if(distance(Segment(a, b), c.p) > c.r - EPS) return c.r * c.r * arg(vb * conj(va));

        auto u = crosspoint(c, Segment(a, b));

        vector< Point > tot{a, u.first, u.second, b};

        for(int i = 0; i + 1 < tot.size(); i++) {

            ret += cross_area(c, tot[i], tot[i + 1]);

        }

        return ret;

    };

    Real A = 0;

    for(int i = 0; i < p.size(); i++) {

        A += cross_area(c, p[i], p[(i + 1) % p.size()]);

    }

    return A;

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_4_B

// 凸多角形の直径(最遠頂点対間距離)

Real convex_diameter(const Polygon &p) {

    int N = (int) p.size();

    int is = 0, js = 0;

    for(int i = 1; i < N; i++) {

        if(p[i].imag() > p[is].imag()) is = i;

        if(p[i].imag() < p[js].imag()) js = i;

    }

    Real maxdis = norm(p[is] - p[js]);



    int maxi, maxj, i, j;

    i = maxi = is;

    j = maxj = js;

    do {

        if(cross(p[(i + 1) % N] - p[i], p[(j + 1) % N] - p[j]) >= 0) {

            j = (j + 1) % N;

        } else {

            i = (i + 1) % N;

        }

        if(norm(p[i] - p[j]) > maxdis) {

            maxdis = norm(p[i] - p[j]);

            maxi = i;

            maxj = j;

        }

    } while(i != is || j != js);

    return sqrt(maxdis);

}



// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_5_A

// 最近点対

Real closest_pair(Points ps) {

    if(ps.size() <= 1) throw (0);

    sort(begin(ps), end(ps));



    auto compare_y = [&](const Point &a, const Point &b) {

        return imag(a) < imag(b);

    };

    vector< Point > beet(ps.size());

    const Real INF = 1e18;



    function< Real(int, int) > rec = [&](int left, int right) {

        if(right - left <= 1) return INF;

        int mid = (left + right) >> 1;

        auto x = real(ps[mid]);

        auto ret = min(rec(left, mid), rec(mid, right));

        inplace_merge(begin(ps) + left, begin(ps) + mid, begin(ps) + right, compare_y);

        int ptr = 0;

        for(int i = left; i < right; i++) {

            if(abs(real(ps[i]) - x) >= ret) continue;

            for(int j = 0; j < ptr; j++) {

                auto luz = ps[i] - beet[ptr - j - 1];

                if(imag(luz) >= ret) break;

                ret = min(ret, abs(luz));

            }

            beet[ptr++] = ps[i];

        }

        return ret;

    };

    return rec(0, (int) ps.size());

}



int main(){

    cin.tie(nullptr);

    ios::sync_with_stdio(false);

    istream& in(cin);

    ostream& out(cout);

    int n,k,x,y;

    in>>n>>k;

    vector<Point> ps(n);

    vector<int> c(n);

    fr(i,n){

        in>>x>>y>>c[i];

        ps[i]=Point(x,y);

    }

    double l=0,r=1e6,m;

    fr(_,100){

        m=(l+r)/2;

        vector<Circle> v(n);

        vector<Point> t;

        fr(i,n) t.push_back(ps[i]);

        fr(i,n) v[i]=Circle(ps[i],m/c[i]);

        fr(i,n) fr(j,i){

                auto cs=crosspoint(v[i],v[j]);

                if(!std::isnan(cs.first.real())){

                    if(abs(cs.first.real())<1000.1&&abs(cs.first.imag())<1000.1) t.push_back(cs.first);

                    if(abs(cs.second.real())<1000.1&&abs(cs.second.imag())<1000.1) t.push_back(cs.second);

                }

            }

        int ans{};

        for(auto p:t){

            int tmp{};

            fr(i,n) if(distance(p,ps[i])<v[i].r+EPS) ++tmp;

            if(tmp>ans) ans=tmp;

        }

        if(ans<k) l=m;

        else r=m;

    }

    cout<<setprecision(20)<<r<<endl;

}


// Faster C++ solution for the same problem (measured speedup: 1.1471033326540168x):
#include<bits/stdc++.h>

using namespace std;

using ll=long long;

#define fr(i,n) for(int i=0;i<(n);++i)

#define Fr(i,n) for(int i=1;i<=(n);++i)

#define ifr(i,n) for(int i=(n)-1;i>=0;--i)

#define iFr(i,n) for(int i=(n);i>0;--i)



namespace geo{

    struct RN{

        constexpr static double eps{1e-9};

        double x;

        constexpr RN(double x=0):x(x){}

        bool operator<(const RN a)const{return eps<a.x-x;}

        bool operator>(const RN a)const{return eps<x-a.x;}

        bool operator<=(const RN a)const{return -eps<a.x-x;}

        bool operator>=(const RN a)const{return -eps<x-a.x;}

        bool operator==(const RN a)const{return -eps<a.x-x&&a.x-x<eps;}

        bool operator!=(const RN a)const{return a.x-x<-eps||eps<a.x-x;}

        RN operator+(const RN a)const{return RN{x+a.x};}

        RN operator-(const RN a)const{return RN{x-a.x};}

        RN operator*(const RN a)const{return RN{x*a.x};}

        RN operator/(const RN a)const{return RN{x/a.x};}

        RN& operator+=(const RN a){x+=a.x;return *this;}

        RN& operator-=(const RN a){this->x-=a.x;return *this;}

        RN& operator*=(const RN a){this->x*=a.x;return *this;}

        RN& operator/=(const RN a){this->x/=a.x;return *this;}

    };

    istream& operator>>(istream &in,RN& x){

        double x_;

        in>>x_;

        x=RN{x_};

        return in;

    }

    ostream& operator<<(ostream &out,const RN& x){

        return out<<x.x;

    }



    constexpr RN pi{3.1415926535897932384626};

    using T=RN;



    struct Point{

        T x,y;

        explicit Point(T x=0,T y=0):x(x),y(y){}

        Point operator+(const Point& a)const{return Point(x+a.x,y+a.y);}

        Point operator-(const Point& a)const{return Point(x-a.x,y-a.y);}

        Point&operator+=(const Point& a){x+=a.x;y+=a.y;return *this;}

        Point&operator-=(const Point& a){x-=a.x;y-=a.y;return *this;}

        Point operator*(const T&c)const{ return Point(x*c,y*c);}

        Point operator/(const T&c)const{ return Point(x/c,y/c);}

        T operator*(const Point& a)const{return x*a.x+y*a.y;}

        T operator^(const Point& a)const{return x*a.y-y*a.x;}

        bool operator<(const Point& a)const{

            if(y==0&&x<0) return !(a.y==0&&a.x<0);

            if(a.y==0&&a.x<0) return false;

            if(y>=0){

                if(a.y<0) return false;

                return (*this^a)>0;

            }

            else{

                if(a.y>=0) return true;

                return (*this^a)>0;

            }

        }

        Point rot(double theta)const{

            T c{cos(theta)},s(sin(theta));

            return Point(x*c-y*s,x*s+y*c);

        }

        T norm()const{

            return x*x+y*y;

        }

        T dis(){

            return sqrt(norm().x);

        }

        T arg(){

            return atan2(y.x,x.x);

        }

    };

    istream& operator>>(istream &in,Point& a){

        return in>>a.x>>a.y;

    }

    ostream& operator<<(ostream &out,const Point& a){

        return out<<"("<<a.x<<","<<a.y<<")";

    }

    T dis(const Point&a,const Point&b){return (a-b).dis();}



    short ccw(const Point&a,Point b,Point c){

        b-=a;c-=a;

        if((b^c)>0) return 1;

        if((b^c)<0) return -1;

        if((b*c)<0) return 2;

        if(b.norm()<c.norm()) return -2;

        return 0;

    }



    struct Line{

        Point a,b;

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

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

        Line(T x, T y,T X,T Y):a(x,y),b(X,Y){}

        Line(T A,T B,T C){

            if(A==0) a=Point(0,C/B),b=Point(1,C/B);

            else if(B==0) a=Point(C/A,0),b=Point(C/A,1);

            else a=Point(0,C/B),b=Point(C/A,0);

        }

    };

    istream& operator>>(istream &in,Line& a){

        return in>>a.a>>a.b;

    }

    ostream& operator<<(ostream &out,const Line& a){

        return out<<a.a<<" to "<<a.b;

    }

    bool para(const Line&a,const Line&b){return ((a.b-a.a)^(b.b-b.a))==0;}

    bool orth(const Line&a,const Line&b){return ((a.b-a.a)*(b.b-b.a))==0;}



    Point proj(const Line&l,const Point&p){

        T t=(p-l.a)*(l.a-l.b)/(l.a-l.b).norm();

        return l.a+(l.a-l.b)*t;

    }



    Point ref(const Line&l,const Point&p){

        return p+(proj(l,p)-p)*2.0;

    }



    T dis(const Line&l,const Point&p){

        return dis(p,proj(l,p));

    }



    T dis(const Point&p,const Line&l){

        return dis(l,p);

    }



    Point cross(const Line&x,const Line&y){

        T a=(x.b-x.a)^(y.b-y.a);

        T b=(x.b-x.a)^(x.b-y.a);

        if(a==0&&b==0) return y.a;

        return y.a+(y.b-y.a)*(b/a);

    }



    short sgn(T x){

        if(x>0) return 1;

        if(x<0) return -1;

        return 0;

    }



    bool iscross(const Line&x,const Line&y){

        T asx=x.a.x,asy=x.a.y,atx=x.b.x,aty=x.b.y;

        T bsx=y.a.x,bsy=y.a.y,btx=y.b.x,bty=y.b.y;

        return sgn((asx-bsx)*(bsy-bty)+(asy-bsy)*(btx-bsx))*sgn((atx-bsx)*(bsy-bty)+(aty-bsy)*(btx-bsx))<=0

               &&sgn((bsx-asx)*(asy-aty)+(bsy-asy)*(atx-asx))*sgn((btx-asx)*(asy-aty)+(bty-asy)*(atx-asx))<=0;

        //strict-> ==-1

    }



    struct Circle{

        Point p;

        RN r;

        Circle()= default;

        Circle(Point p,RN r):p(p),r(r){}

        Circle(RN a,RN b,RN r):p(a,b),r(r){}

    };



    ostream& operator<<(ostream &out,const Circle& c){

        return out<<"("<<c.p<<","<<c.r<<")";

    }



    pair<Point,Point> cross(const Circle&c1,const Circle&c2){

        T d=dis(c1.p,c2.p);

        T a=acos(((c1.r*c1.r+d*d-c2.r*c2.r)/(c1.r*d*2)).x);

        T t=atan2((c2.p.y-c1.p.y).x,(c2.p.x-c1.p.x).x);

        Point p1=c1.p+Point(cos((t+a).x),sin((t+a).x))*c1.r;

        Point p2=c1.p+Point(cos((t-a).x),sin((t-a).x))*c1.r;

        return {p1,p2};

    }



    pair<Point,Point> cross(const Circle&c,const Line&l){

        Point p=proj(l,c.p);

        Point e=(l.b-l.a)/dis(l.a,l.b);

        if(dis(l,c.p)==c.r) return {p,p};

        double b=sqrt((c.r*c.r-(p-c.p).norm()).x);

        return {p-e*b,p+e*b};

    }



    vector<Point> convex_hull(vector<Point>&vp){

        int n=vp.size(),k{};

        if(n<=2) return vp;

        sort(vp.begin(),vp.end(),[](const Point&a,const Point&b){

            return a.x==b.x?a.y<b.y:a.x<b.x;

        });

        vector<Point> ch(2*n);

        for(int i=0;i<n;ch[k++]=vp[i++]){

            while(k>=2&&((ch[k-1]-ch[k-2])^(vp[i]-ch[k-1]))<=0) --k;

        }

        for(int i=n-2,t=k+1;i>=0;ch[k++]=vp[i--]){

            while(k>=t&&((ch[k-1]-ch[k-2])^(vp[i]-ch[k-1]))<=0) --k;

        }

        ch.resize(k-1);

        return ch;

    }

}

using namespace geo;



int main(){

    cin.tie(nullptr);

    ios::sync_with_stdio(false);

    istream& in(cin);

    ostream& out(cout);

    int n,k,x,y;

    in>>n>>k;

    vector<Point> ps(n);

    vector<int> c(n);

    fr(i,n){

        in>>x>>y>>c[i];

        ps[i]=Point(x,y);

    }

    double l=0,r=1e6,m;

    fr(_,50){

        m=(l+r)/2;

        vector<Circle> v(n);

        vector<Point> t;

        fr(i,n) v[i]=Circle(ps[i],m/c[i]);

        fr(i,n){

            t.push_back(ps[i]);

            fr(j,i){

                auto cs=cross(v[i],v[j]);

                if(!std::isnan(cs.first.x.x)){

                    if(abs(cs.first.x.x)<1000.1&&abs(cs.first.y.x)<1000.1)t.push_back(cs.first);

                    if(abs(cs.second.x.x)<1000.1&&abs(cs.second.y.x)<1000.1)t.push_back(cs.second);

                }

            }

        }

        bool F{};

        int tmp{};

        for(auto p:t){

            tmp=0;

            fr(i,n) if(dis(p,ps[i])<=v[i].r) ++tmp;

            if(tmp>=k){

                F=true;

                break;

            }

        }

        if(F) r=m;

        else l=m;

    }

    cout<<setprecision(20)<<r<<endl;

}