#include <bits/stdc++.h>
// created [2020/03/06] 20:38:38
#pragma GCC diagnostic ignored "-Wsign-compare"
#pragma GCC diagnostic ignored "-Wsign-conversion"

using i32   = int32_t;
using i64   = int64_t;
using u32   = uint32_t;
using u64   = uint64_t;
using uint  = unsigned int;
using usize = std::size_t;
using ll    = long long;
using ull   = unsigned long long;
using ld    = long double;
template<typename T, usize n>
using arr = T (&)[n];
template<typename T, usize n>
using c_arr = const T (&)[n];
template<typename T>
using max_heap = std::priority_queue<T>;
template<typename T>
using min_heap = std::priority_queue<T, std::vector<T>, std::greater<T>>;
template<typename T> constexpr T popcount(const T u) { return u ? static_cast<T>(__builtin_popcountll(static_cast<u64>(u))) : static_cast<T>(0); }
template<typename T> constexpr T log2p1(const T u) { return u ? static_cast<T>(64 - __builtin_clzll(static_cast<u64>(u))) : static_cast<T>(0); }
template<typename T> constexpr T msbp1(const T u) { return log2p1(u); }
template<typename T> constexpr T lsbp1(const T u) { return __builtin_ffsll(u); }
template<typename T> constexpr T clog(const T u) { return u ? log2p1(u - 1) : static_cast<T>(u); }
template<typename T> constexpr bool ispow2(const T u) { return u and (static_cast<u64>(u) & static_cast<u64>(u - 1)) == 0; }
template<typename T> constexpr T ceil2(const T u) { return static_cast<T>(1) << clog(u); }
template<typename T> constexpr T floor2(const T u) { return u == 0 ? static_cast<T>(0) : static_cast<T>(1) << (log2p1(u) - 1); }
template<typename T> constexpr bool btest(const T mask, const usize ind) { return static_cast<bool>((static_cast<u64>(mask) >> ind) & static_cast<u64>(1)); }
template<typename T> void bset(T& mask, const usize ind) { mask |= (static_cast<T>(1) << ind); }
template<typename T> void breset(T& mask, const usize ind) { mask &= ~(static_cast<T>(1) << ind); }
template<typename T> void bflip(T& mask, const usize ind) { mask ^= (static_cast<T>(1) << ind); }
template<typename T> void bset(T& mask, const usize ind, const bool b) { (b ? bset(mask, ind) : breset(mask, ind)); }
template<typename T> constexpr T bcut(const T mask, const usize ind) { return ind == 0 ? static_cast<T>(0) : static_cast<T>((static_cast<u64>(mask) << (64 - ind)) >> (64 - ind)); }
template<typename T> bool chmin(T& a, const T& b) { return (a > b ? a = b, true : false); }
template<typename T> bool chmax(T& a, const T& b) { return (a < b ? a = b, true : false); }
constexpr unsigned int mod                  = 1000000007;
template<typename T> constexpr T inf_v      = std::numeric_limits<T>::max() / 4;
template<typename Real> constexpr Real pi_v = Real{3.141592653589793238462643383279502884};
auto mfp = [](auto&& f) { return [=](auto&&... args) { return f(f, std::forward<decltype(args)>(args)...); }; };

template<typename T>
T in()
{
    T v;
    return std::cin >> v, v;
}
template<typename T, typename Uint, usize n, usize i>
T in_v(typename std::enable_if<(i == n), c_arr<Uint, n>>::type) { return in<T>(); }
template<typename T, typename Uint, usize n, usize i>
auto in_v(typename std::enable_if<(i < n), c_arr<Uint, n>>::type& szs)
{
    const usize s = (usize)szs[i];
    std::vector<decltype(in_v<T, Uint, n, i + 1>(szs))> ans(s);
    for (usize j = 0; j < s; j++) { ans[j] = in_v<T, Uint, n, i + 1>(szs); }
    return ans;
}
template<typename T, typename Uint, usize n>
auto in_v(c_arr<Uint, n> szs) { return in_v<T, Uint, n, 0>(szs); }
template<typename... Types>
auto in_t() { return std::tuple<std::decay_t<Types>...>{in<Types>()...}; }
struct io_init
{
    io_init()
    {
        std::cin.tie(nullptr), std::ios::sync_with_stdio(false);
        std::cout << std::fixed << std::setprecision(20);
    }
    void clear()
    {
        std::cin.tie(), std::ios::sync_with_stdio(true);
    }
} io_setting;

int out() { return 0; }
template<typename T>
int out(const T& v) { return std::cout << v, 0; }
template<typename T>
int out(const std::vector<T>& v)
{
    for (usize i = 0; i < v.size(); i++) {
        if (i > 0) { std::cout << ' '; }
        out(v[i]);
    }
    return 0;
}
template<typename T1, typename T2>
int out(const std::pair<T1, T2>& v) { return out(v.first), std::cout << ' ', out(v.second), 0; }
template<typename T, typename... Args>
int out(const T& v, const Args... args) { return out(v), std::cout << ' ', out(args...), 0; }
template<typename... Args>
int outln(const Args... args) { return out(args...), std::cout << '\n', 0; }
template<typename... Args>
int outel(const Args... args) { return out(args...), std::cout << std::endl, 0; }
#    define SHOW(...) static_cast<void>(0)
constexpr ull TEN(const usize n) { return n == 0 ? 1ULL : TEN(n - 1) * 10ULL; }

template<typename T, typename Uint, usize n, usize i>
auto make_v(typename std::enable_if<(i == n), c_arr<Uint, n>>::type, const T& v = T{}) { return v; }
template<typename T, typename Uint, usize n, usize i>
auto make_v(typename std::enable_if<(i < n), c_arr<Uint, n>>::type szs, const T& v = T{})
{
    const usize s = (usize)szs[i];
    return std::vector<decltype(make_v<T, Uint, n, i + 1>(szs, v))>(s, make_v<T, Uint, n, i + 1>(szs, v));
}
template<typename T, typename Uint, usize n>
auto make_v(c_arr<Uint, n> szs, const T& t = T{}) { return make_v<T, Uint, n, 0>(szs, t); }
int main()
{
    constexpr ld eps = 1e-6;
    const auto N     = in<int>();
    const auto K     = in<int>();
    std::vector<ld> xs(N), ys(N), cs(N);
    for (int i = 0; i < N; i++) { xs[i] = in<ld>(), ys[i] = in<ld>(), cs[i] = in<ld>(); }
    if (K == 1) { return outln(0); }
    auto ok = [&](const ld tim) -> bool {
        std::vector<ld> rs(N);
        for (int i = 0; i < N; i++) { rs[i] = tim / cs[i]; }
        for (int i = 0; i < N; i++) {
            const ld cx = xs[i], cy = ys[i];
            int cnt = 0;
            for (int k = 0; k < N; k++) {
                const ld xk = xs[k], yk = ys[k];
                const ld rk = rs[k];
                if (std::hypot(cx - xk, cy - yk) <= rk + eps) { cnt++; }
            }
            if (cnt >= K) { return true; }
        }
        for (int i = 0; i < N; i++) {
            const ld xi = xs[i], yi = ys[i];
            const ld ri = rs[i];
            for (int j = i + 1; j < N; j++) {
                const ld xj = xs[j], yj = ys[j];
                const ld rj = rs[j];
                const ld R  = std::hypot(xi - xj, yi - yj);
                if (ri + rj + eps < R) { continue; }
                if (std::abs(ri - rj) > R + eps) { continue; }
                const ld s  = (R * R + ri * ri - rj * rj) / (2 * R);
                const ld t  = std::abs(s * s - ri * ri) < eps ? (ld)0 : std::sqrt(ri * ri - s * s);
                const ld px = (xj - xi) / R, py = (yj - yi) / R;
                const ld qx = -py, qy = px;

                const ld cxs[] = {px * s + qx * t, px * s - qx * t}, cys[] = {py * s + qy * t, py * s - qy * t};
                for (int l = 0; l < 2; l++) {
                    const ld cx = xi + cxs[l], cy = yi + cys[l];
                    int cnt = 0;
                    for (int k = 0; k < N; k++) {
                        const ld xk = xs[k], yk = ys[k];
                        const ld rk = rs[k];
                        if (std::hypot(cx - xk, cy - yk) <= rk + eps) { cnt++; }
                    }
                    if (cnt >= K) { return true; }
                }
            }
        }
        return false;
    };
    SHOW(ok(7411.2252));
    SHOW(ok(7412.2252));
    SHOW(ok(7812.5));
    ld inf = 0, sup = 1000000;
    for (int i = 0; i < 60; i++) {
        const ld mid          = (inf + sup) / 2;
        (ok(mid) ? sup : inf) = mid;
    }
    outln(sup);
    return 0;
}


Measured memory_bytes: 256