#include <bits/stdc++.h>
using namespace std;
using lint = long long int;
using pint = pair<int, int>;
using plint = pair<lint, lint>;
struct fast_ios { fast_ios(){ cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_;
#define ALL(x) (x).begin(), (x).end()
#define SZ(x) ((lint)(x).size())
#define POW2(n) (1LL << (n))
#define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i<i##_end_;i++)
#define IFOR(i, begin, end) for(int i=(end)-1,i##_begin_=(begin);i>=i##_begin_;i--)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
template<typename T> istream &operator>>(istream &is, vector<T> &vec){ for (auto &v : vec) is >> v; return is; }
template<typename T> ostream &operator<<(ostream &os, const vector<T> &vec){ os << "["; for (auto v : vec) os << v << ","; os << "]"; return os; }
template<typename T> ostream &operator<<(ostream &os, const deque<T> &vec){ os << "deq["; for (auto v : vec) os << v << ","; os << "]"; return os; }
template<typename T> ostream &operator<<(ostream &os, const set<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T> ostream &operator<<(ostream &os, const unordered_set<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T> ostream &operator<<(ostream &os, const multiset<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T> ostream &operator<<(ostream &os, const unordered_multiset<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &pa){ os << "(" << pa.first << "," << pa.second << ")"; return os; }
template<typename TK, typename TV> ostream &operator<<(ostream &os, const map<TK, TV> &mp){ os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; }
template<typename TK, typename TV> ostream &operator<<(ostream &os, const unordered_map<TK, TV> &mp){ os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; }
template<typename T> void ndarray(vector<T> &vec, int len) { vec.resize(len); }
template<typename T, typename... Args> void ndarray(vector<T> &vec, int len, Args... args) { vec.resize(len); for (auto &v : vec) ndarray(v, args...); }
template<typename T> bool mmax(T &m, const T q) { if (m < q) {m = q; return true;} else return false; }
template<typename T> bool mmin(T &m, const T q) { if (q < m) {m = q; return true;} else return false; }
template<typename T1, typename T2> pair<T1, T2> operator+(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first + r.first, l.second + r.second); }
template<typename T1, typename T2> pair<T1, T2> operator-(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first - r.first, l.second - r.second); }
#define dbg(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ") " << __FILE__ << endl;
/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/tag_and_trait.hpp>
using namespace __gnu_pbds; // find_by_order(), order_of_key()
template<typename TK> using pbds_set = tree<TK, null_type, less<TK>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename TK, typename TV> using pbds_map = tree<TK, TV, less<TK>, rb_tree_tag, tree_order_statistics_node_update>;
*/

using T_P = double;
constexpr T_P EPS = 1E-8;
struct P
{
    T_P x, y;
    P(T_P x = 0, T_P y = 0) : x(x), y(y) {}
    P(pair<T_P, T_P> p) : x(p.first), y(p.second) {}
    static T_P add_w_error(T_P a, T_P b) { return (abs(a + b) < EPS * (abs(a) + abs(b))) ? 0 : a + b; }
    P operator+(const P &p) const { return P(add_w_error(x, p.x), add_w_error(y, p.y)); }
    P operator-(const P &p) const { return P(add_w_error(x, -p.x), add_w_error(y, -p.y)); }
    P operator*(const P &p) const { return P(add_w_error(x * p.x,  -y * p.y), add_w_error(x * p.y, y * p.x)); }
    P operator*(T_P d) const { return P(x * d, y * d); }
    P operator/(T_P d) const { return P(x / d, y / d); }
    P inv() const { return conj() / norm2(); }
    P operator/(const P &p) const { return (*this) * p.inv(); }
    bool operator<(const P &r) const{ return x != r.x ? x < r.x : y < r.y; }
    bool operator==(const P &r) const{ return add_w_error(x, -r.x) == 0 and add_w_error(y, -r.y) == 0; }
    T_P dot(P p) const { return add_w_error(x * p.x, y * p.y); }
    T_P det(P p) const { return add_w_error(x * p.y, -y * p.x); }
    T_P norm() const { return sqrt(x * x + y * y); }
    T_P norm2() const { return x * x + y * y; }
    T_P arg() const { return atan2(y, x); }
    // rotate point/vector by rad
    P rotate(T_P rad) { return P(add_w_error(x * cos(rad), -y * sin(rad)), add_w_error(x * sin(rad), y * cos(rad))); }
    P conj() const { return P(x, -y); }
    friend istream &operator>>(istream &is, P &p) { T_P x, y; is >> x >> y; p = P(x, y); return is; }
    friend ostream &operator<<(ostream &os, const P &p) { os << '(' << p.x << ',' << p.y << ')'; return os; }
};

vector<P> sol(P a, P b, double Ra, double Rb) {
    double d = (a - b).norm();
    double rc = (d * d + Ra * Ra - Rb * Rb) / (2 * d);
    double rs = sqrt(Ra * Ra - rc * rc);
    P diff = (b - a) / d;
    return {a + diff * P(rc, rs), a + diff * P(rc, -rs)};
}

int main()
{
    int N, K;
    cin >> N >> K;
    double lo = 0.0, hi = 1.0e9;
    vector<double> X(N), Y(N), C(N);
    vector<P> Center(N);
    REP(i, N) cin >> X[i] >> Y[i] >> C[i];
    REP(i, N) Center[i] = P(X[i], Y[i]);
    REP(d, 100)
    {
        double t = (lo + hi) / 2;
        vector<double> R(N);
        REP(i, N) R[i] = t / C[i];
        int maxi = 0;
        REP(i, N) REP(j, N) {
            vector<P> vp{Center[i]};
            if (i != j and (Center[i] - Center[j]).norm() < R[i] + R[j]) {
                vp = sol(Center[i], Center[j], R[i], R[j]);
            }
            for (auto p : vp)
            {
                int cnt = 0;
                REP(i, N) if ((Center[i] - p).norm() <= R[i] + EPS) cnt++;
                mmax(maxi, cnt);
            }
        }
        (maxi >= K ? hi : lo) = t;
    }
    cout << lo << endl;
}


Measured memory_bytes: 384