#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:>
 問題文============================================================
 =================================================================
 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();
}
}  // namespace std
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;
}
// 円と直線の交点
vector<Point> is_lc(Circle c, Line l) {
    vector<Point> res;
    ld d = dist_lp(l, c.p);
    if (d < c.r + eps) {
        ld len = (d > c.r) ? 0.0 : sqrt(c.r * c.r - d * d);  // safety;
        Point nor = (l.a - l.b) / abs(l.a - l.b);
        res.push_back(proj(l, c.p) + len * nor);
        res.push_back(proj(l, c.p) - len * nor);
    }
    return res;
}
// 円と線分の距離
vector<Point> is_sc(Circle c, Line l) {
    vector<Point> v = is_lc(c, l), res;
    for (Point p : v)
        if (isis_sp(l, p)) res.push_back(p);
    return res;
}
// 円と点の接線
vector<Line> tangent_cp(Circle c, Point p) {
    vector<Line> ret;
    Point v = c.p - p;
    ld d = abs(v);
    ld l = sqrt(norm(v) - c.r * c.r);
    if (isnan(l)) {
        return ret;
    }
    Point v1 = v * Point(l / d, c.r / d);
    Point v2 = v * Point(l / d, -c.r / d);
    ret.push_back(Line(p, p + v1));
    if (l < eps) return ret;
    ret.push_back(Line(p, p + v2));
    return ret;
}
// 円と円の接線
vector<Line> tangent_cc(Circle c1, Circle c2) {
    vector<Line> ret;
    if (abs(c1.p - c2.p) - (c1.r + c2.r) > -eps) {
        Point center = (c1.p * c2.r + c2.p * c1.r) / (c1.r + c2.r);
        ret = tangent_cp(c1, center);
    }
    if (abs(c1.r - c2.r) > eps) {
        Point out = (-c1.p * c2.r + c2.p * c1.r) / (c1.r - c2.r);
        vector<Line> nret = tangent_cp(c1, out);
        ret.insert(ret.end(), nret.begin(), nret.end());
    } else {
        Point v = c2.p - c1.p;
        v /= abs(v);
        Point q1 = c1.p + v * Point(0, 1) * c1.r;
        Point q2 = c1.p + v * Point(0, -1) * c1.r;
        ret.push_back(Line(q1, q1 + v));
        ret.push_back(Line(q2, q2 + v));
    }
    return ret;
}

template <class Type>
Type solve(Type res = Type()) {
    int N, K;
    cin >> N >> K;

    vector<int> x(N), y(N), c(N);
    for (int i = 0; i < N; i++) {
        cin >> x[i] >> y[i] >> c[i];
    }

    auto check = [&](double m) {
        vector<Circle> Cs(N);
        for (int i = 0; i < N; i++) {
            Cs[i].p = Point(x[i], y[i]);
            Cs[i].r = m / c[i];
        }
        vector<Point> cands;

        for (int i = 0; i < N; i++) {
            cands.emplace_back(Cs[i].p);
            for (int j = i + 1; j < N; j++) {
                for (const Point& p : is_cc(Cs[i], Cs[j])) {
                    cands.emplace_back(p);
                }
            }
        }

        bool ok = false;

        for(const Point& p:cands){
            int cnt = 0;
            for(int i = 0; i < N;i++){
                if(abs(Cs[i].p-p) < Cs[i].r + eps){
                    cnt++;
                }
            }
            if(cnt >= K){
                ok = true;
                break;
            }
        }

        return ok;
    };

    double l = 0, r = INF;
    for (int unchi = 0; unchi < 300; unchi++) {
        double m = (l + r) / 2;

        if(check(m)){
            r = m;
        }else{
            l = m;
        }
    }
    res = r;
    return res;
}
int main(void) {
    cin.tie(0);
    ios::sync_with_stdio(false);
    // solve<ll>(0);
    cout << fixed << setprecision(12) << solve<double>() << endl;
    return 0;
}

Measured memory_bytes: 3936