#include <bits/stdc++.h>

using namespace std; const int maxn = 1e5 + 5;


int n, k, sx[maxn], sy[maxn];

struct node { double x, y; } a[maxn];

double f[maxn];

inline bool check(double g)
{
  int ans = 0;
  for (int i = 1; i <= n; i++) a[i] = { sx[i], sy[i] - sx[i] * g };
//  sort(a + 1, a + n + 1, [](auto u, auto v) { return u.x < v.x; });
  for (int i = 1; i <= n; i++) f[i] = 4e18;
  for (int i = 1; i <= n; i++)
  {
//    cerr << a[i].y << ' ';
    int x = upper_bound(f + 1, f + n + 1, a[i].y) - f;
    f[x] = a[i].y;
    ans = max(ans, x);
  }
//  cerr << endl;
//  cerr << g << ' ' << ans << endl;
  return ans >= k;
}

int main()
{
  scanf("%d%d", &n, &k);
  for (int i = 1; i <= n; i++) scanf("%d%d", sx + i, sy + i);
//  cerr << check(-1.5) << endl;
  double l = -2e9 - 5, r = 2e9;
  for(int i=0;i<50;i++)
  {
    double mid = (l + r) * 0.5;
    if (check(mid)) l = mid; else r = mid;
  }
  return 0 * printf("%.8lf\n", l);
}