#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
// #define int long long
#define double long double
#define rep(i,n) for (int i=0; i<(int)(n); ++i)
#define rep1(i,n) for (int i=1; i<(int)(n); ++i)
#define repeq(i,n) for (int i=0; i<=(int)(n); ++i)
#define rep1eq(i,n) for (int i=1; i<=(int)(n); ++i)
#define rrep(i,n) for (int i=(int)(n)-1; i>=0; --i)
#define rrep1(i,n) for (int i=(int)(n)-1; i>0; --i)
#define rrepeq(i,n) for (int i=(int)(n); i>=0; --i)
#define rrep1eq(i,n) for (int i=(int)(n); i>0; --i)
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
using ll = long long;
using vi = vector<int>;
using vl = vector<ll>;
using vb = vector<bool>;
template<typename T> using Graph = vector<vector<T>>;
template<typename T> using Spacial = vector<vector<vector<T>>>;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
const int MOD = 1e9+7;
const int MOD2 = 998244353;
// const double EPS = 1e-9;
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};
string interval[2] = {" ", "\n"};

template<typename T> struct is_pair : false_type{};
template<typename T1, typename T2> struct is_pair<pair<T1, T2>> : true_type{};
template<typename T> struct is_vector : false_type{};
template<typename T> struct is_vector<vector<T>> : true_type{};

template<typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) {
  is >> p.first >> p.second;
  return is;
} 
template<typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
  os << p.first << " " << p.second;
  return os;
}
template<typename T>
istream &operator>>(istream &is, vector<T> &vec) {
  for (auto itr = vec.begin(); itr != vec.end(); ++itr) {
    is >> *itr;
  }
  return is;
}
template<typename T>
ostream &operator<<(ostream &os, const vector<T> &vec) {
  if (vec.empty()) return os;
  bool vp = is_vector<T>() || is_pair<T>();
  os << vec.front();
  for (auto itr = ++vec.begin(); itr != vec.end(); ++itr) {
    os << interval[vp] << *itr;
  }
  return os;
}

bool CoutYN(bool a, string y = "Yes", string n = "No") {
  cout << (a ? y : n) << "\n";
  return a;
}

template<typename T1, typename T2>
inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }
template<typename T1, typename T2>
inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }

int modpow(int a, long long n, int mod = MOD) {
  int ret = 1;
  do {
    if (n & 1) ret = 1LL * ret * a % mod;
    a = 1LL * a * a % mod;
  } while (n >>= 1);
  return ret;
}

template<typename T>
T GCD(T a, T b) { return b ? GCD(b, a%b) : a; }
template<typename T>
T LCM(T a, T b) { return a / GCD(a, b) * b; }

template<typename T1, typename T2>
bool CompareBySecond(pair<T1, T2> a, pair<T1, T2> b) {
  return a.second != b.second ? a.second < b.second : a.first < b.first;
}
template<typename T>
bool CompareBySlope(pair<T, T> a, pair<T, T> b) {
// counterclockwise from 12 o'clock direction
  if (a.first * b.first < 0) return a.first < b.first;
  if (a.first == 0) return a.second >= 0 || b.first > 0;
  if (b.first == 0) return b.second < 0 && a.first < 0;
  return a.second * b.first < a.first * b.second;
}


/* -------- <templates end> -------- */


using Real = double;
using Point = complex<Real>;
const Real EPS = 1e-9, 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 << p.real() << " " << p.imag();
}

// Rotate point p theta counterclockwise
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);
}

// Return the lesser of the a-b-c angles
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) {}

// Ax + By = C
  Line(Real A, Real B, Real 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);
}

// Rotation direction of the point
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"
}

bool parallel(const Line &a, const Line &b) {
  return eq(cross(a.b - a.a, b.b - b.a), 0.0);
}

bool orthogonal(const Line &a, const Line &b) {
  return eq(dot(a.a - a.b, b.a - b.b), 0.0);
}

// Find the foot of the perpendicular line
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;
}

// Find the point of linear symmetry
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;
}

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;
}

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));
}

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;
}

Point crosspoint(const Segment &l, const Segment &m) {
  return crosspoint(Line(l), Line(m));
}

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;
}

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};
}

// Tangent line of the circle c passing through the point p
pair<Point, Point> tangent(const Circle &c1, const Point &p2) {
  return crosspoint(c1, Circle(p2, sqrt(norm(c1.p - p2) - c1.r * c1.r)));
}

// Common tangent of circles c1, c2
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;
}

Points g;
vector<Real> cook;

int yakiniku(Point &c, Real &time) {
  int cnt = 0;
  int n = g.size();
  rep(i,n) {
    if (cook[i] * abs(c - g[i]) <= time + EPS) {
      ++cnt;
    }
  }
  return cnt;
}

bool pushback(Lines &li, Circles &ci, Point &m, int i, int j) {
  if (cook[i] == cook[j]) {
    Point u = g[j] - g[i];
    Point v = rotate(PI * 0.5, u);
    li.emplace_back(m, m + v);
    return true;
  }

  Point d = (cook[i] * g[i] - cook[j] * g[j]) / (cook[i] - cook[j]);
  Point c = (d + m) * 0.5;
  ci.emplace_back(c, abs(c - d));
  return false;
}

void solve() {
  int n, k; cin >> n >> k;
  g.resize(n);
  cook.resize(n);
  rep(i,n) cin >> g[i] >> cook[i];
  
  if (k == 1) {
    cout << 0 << endl;
    return;
  }

  Real ans = 1e9;
  rep(p,n) {
    rep(q,p) {
      Point m = (cook[p] * g[p] + cook[q] * g[q]) / (cook[p] + cook[q]);
      Real time = cook[p] * abs(m - g[p]);
      if (yakiniku(m, time) >= k) {
        chmin(ans, time);
      }

      Lines li;
      Circles ci;
      pushback(li, ci, m, p, q);

      rep(r,q) {
        if (eq(cross(g[p] - g[q], g[q] - g[r]), 0.0)) continue;

        Point m2 = (cook[q] * g[q] + cook[r] * g[r]) / (cook[q] + cook[r]);
        bool pbline = pushback(li, ci, m2, q, r);

        pair<Point, Point> c;
        if (ci.empty()) {
          c.first = c.second = crosspoint(li[0], li[1]);
        } else if (li.empty()) {
          c = crosspoint(ci[0], ci[1]);
        } else {
          c = crosspoint(ci[0], li[0]);
        }

        Real time1 = cook[p] * abs(c.first - g[p]);
        if (yakiniku(c.first, time1) >= k) {
          chmin(ans, time1);
        }
        Real time2 = cook[p] * abs(c.second - g[p]);
        if (yakiniku(c.second, time2) >= k) {
          chmin(ans, time2);
        }

        if (pbline) {
          li.pop_back();
        } else {
          ci.pop_back();
        }
      }
    }
  }

  cout << ans << endl;
}


/* -------- <programs end> -------- */


signed main() {
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(12);
  solve();
  return 0;
}


Measured memory_bytes: 384