#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>

using namespace std;

#define LL long long 

const int N = 1e5;

struct qwq{
	double x,y;
};
qwq p[N];

int n,k,cnt;
double a[N],b[N],q[N];
double ans;

bool cmp(qwq a,qwq b)
{
	if(a.y != b.y) return a.x < b.x;
	return a.y < b.y;
}

void find(double h,int l,int r)
{
	if(l == r)
	{
		q[l] = h;
		return;
	}
	int mid = (l + r) / 2;
	if(h < q[mid])
		find(h,l,mid);
	else find(h,mid + 1,r);
}

bool check(double slp)
{
	if(slp != 0)
		for(int i = 1;i <= n;i ++)
		{
			//p[i].y = abs(slp * a[i] - b[i]) / sqrt(1.0 + (b[i] / a[i]) * (b[i] / a[i]));
			//p[i].x = sqrt(a[i] * a[i] + b[i] * b[i] - p[i].y * p[i].y);
			p[i].y = -slp * a[i] + b[i];
			p[i].x = a[i];
		}
	else
		for(int i = 1;i <= n;i ++)
		{
			p[i].x = a[i];
			p[i].y = b[i];
		}
	//sort(p + 1,p + n + 1,cmp);
	cnt = 0;
	q[0] = -1e9;
	for(int i = 1;i <= n;i ++)
	{
		//printf("p[%d].y = %lf ",i,p[i].y);
		if(p[i].y >= q[cnt]) q[++ cnt] = p[i].y;
		else find(p[i].y,1,cnt);
	}
	/*cout << "height: ";
	for(int i = 1;i <= cnt;i ++)
		printf("%lf ",q[i]);
	cout << "; cnt = " << cnt << endl;*/
	return cnt >= k;
}

int main()
{
	scanf("%d%d",&n,&k);
	for(int i = 1;i <= n;i ++)
		scanf("%lf%lf",&a[i],&b[i]);
	double l = -1e9, r = 1e9;
	while(r - l >= 1e-6)
	{
		double mid = (l + r) / 2;
		//cout << l << " " << r << " " << mid << endl;
		if(check(mid))
		{
			ans = mid;
			l = mid;
		}
		else r = mid;
	}
	l = (int)ans - 3;
	r = (int)ans + 3;
	while(r - l >= 1e-6)
	{
		double mid = (l + r) / 2;
		//cout << l << " " << r << " " << mid << endl;
		if(check(mid))
		{
			ans = mid;
			l = mid;
		}
		else r = mid;
	}
	//cout << check(-1.0) << endl;;
	cout << ans;
	return (0 ^ 0);
}