#include <bits/stdc++.h>
#include <chrono> 
 
using namespace std;
using namespace std::chrono; 
 
// #pragma GCC target ("avx2")
// #pragma GCC optimization ("O3")
// #pragma GCC optimization ("unroll-loops")
// #pragma optimization_level 3
// #pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math,O3")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
 
#define f0r(a, b) for (long long a = 0; a < (b); ++a)
#define f1r(a, b, c) for (long long a = (b); a < (c); ++a)
#define f0rd(a, b) for (long long a = (b); a >= 0; --a)
#define f1rd(a, b, c) for (long long a = (b); a >= (c); --a)
#define ms(arr, v) memset(arr, v, sizeof(arr))
#define pb push_back
#define send {ios_base::sync_with_stdio(false);}
#define help {cin.tie(NULL); cout.tie(NULL);}
#define fix(prec) {cout << setprecision(prec) << fixed;}
#define mp make_pair
#define f first
#define s second
#define presum(p, a, n) {p[0] = a[0]; for (int i = 1; i < (n); i++) p[i] = a[i] + p[i-1];}
#define all(v) v.begin(), v.end()
#define getunique(v) {sort(all(v)); v.erase(unique(all(v)), v.end());}
#define readgraph(list, edges) for (int i = 0; i < edges; i++) {int a, b; cin >> a >> b; a--; b--; list[a].pb(b); list[b].pb(a);}
#define ai(a, n) for (int ele = 0; ele < n; ele++) cin >> a[ele];
#define ain(a, lb, rb) for (int ele = lb; ele <= rb; ele++) cin >> a[ele];
#define ao(a, n) {for (int ele = 0; ele < (n); ele++) { if (ele) cout << " "; cout << a[ele]; } cout << '\n';}
#define aout(a, lb, rb) {for (int ele = (lb); ele <= (rb); ele++) { if (ele > (lb)) cout << " "; cout << a[ele]; } cout << '\n';}
typedef long long ll;
typedef double ld;
typedef long double lld;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<pii> vpi;
typedef vector<pll> vpl;
 
template<typename A> ostream& operator<<(ostream &cout, vector<A> const &v);
template<typename A, typename B> ostream& operator<<(ostream &cout, pair<A, B> const &p) { return cout << "(" << p.f << ", " << p.s << ")"; }
template<typename A> ostream& operator<<(ostream &cout, vector<A> const &v) {
  cout << "["; for(int i = 0; i < v.size(); i++) {if (i) cout << ", "; cout << v[i];} return cout << "]";
}
template<typename A, typename B> istream& operator>>(istream& cin, pair<A, B> &p) {
  cin >> p.first;
  return cin >> p.second;
}
 
// template<typename A, typename B> ll max(A x, B y) {
//   return x > y ? x : y;
// }
// template<typename A, typename B> ll min(A x, B y) {
//   return x < y ? x : y;
// }
 
mt19937 rng(steady_clock::now().time_since_epoch().count());
// mt19937 rng(61378913);
/* usage - just do rng() */
 
void usaco(string filename) {
  // #pragma message("be careful, freopen may be wrong")
	freopen((filename + ".in").c_str(), "r", stdin);
	freopen((filename + ".out").c_str(), "w", stdout);
}
 
const lld pi = 3.14159265358979323846;
// const ll mod = 1000000007;
const ll mod = 998244353;
// ll mod;



ll n, m, k, q, l, r, x, y, z;
ll a[1000005];
ll b[1000005];
ll c[1000005];
string s, t;
ll ans = 0;

using pt = pair<lld, lld>;
pair<lld, pt> pts[65];
pt tries[9007];

const lld eps = 1e-10;

lld sq(lld x) {return x * x;}

lld dist(pt a, pt b) {
  return sqrt(sq(a.f - b.f) + sq(a.s - b.s));
}

pair<pt, pt> isect(pt a, pt b, lld ra, lld rb) {
  lld d = dist(a, b);
  pair<pt, pt> v;
  v.f = mp(-1, -1);

  if (d + eps > ra + rb || d < abs(ra - rb)) {
    return v;
  }

  lld x2 = (b.f - a.f) / d;
  lld y2 = (b.s - a.s) / d;

  lld x = (sq(ra) - sq(rb) + sq(d)) / (2 * d);
  lld y = sqrt(sq(ra) - sq(x));

  v.f = mp(a.f + x * x2 - y * y2, a.s + x * y2 + y * x2);
  v.s = mp(a.f + x * x2 + y * y2, a.s + x * y2 - y * x2);

  return v;
}

bool has_isect(pt v, lld t) {
  int is = 0;
  f0r(i, n) {
    lld d = dist(v, pts[i].s);
    lld r = t / pts[i].f;
    if (d - eps < r) ++is;
  }

  return is >= k;
}

bool can(lld t) {
  f0r(i, n) tries[i] = pts[i].s;

  ll tp = n;
  f0r(i, n) f0r(j, i) {
    lld ri = t / pts[i].f;
    lld rj = t / pts[j].f;

    pair<pt, pt> is = isect(pts[i].s, pts[j].s, ri, rj);
    if (is.f.f != -1) {
      tries[tp++] = is.f;
      tries[tp++] = is.s;
    }
  }

  f0r(i, tp) {
    if (has_isect(tries[i], t)) return true;
  }

  return false;
}

void solve(int tc) {
  cin >> n >> k; fix(13);
  f0r(i, n) {
    cin >> pts[i].s >> pts[i].f;
  }

  lld l = 0, r = 1e8;
  f0r(iter, 100) {
    lld m = (l + r) / 2;

    if (can(m)) r = m;
    else l = m;
  }

  cout << l << '\n';
}

int main() {
  send help

  // usaco("file");

  int tc;
  tc = 1;
  // cin >> tc;
  for (int t = 0; t < tc; t++) solve(t);
} 

Measured memory_bytes: 384