#include<bits/stdc++.h>
using namespace std;
int n,k;
struct node
{
	double m;
	int s,b;
}a[100001];
inline const void read(int &x)
{
	x=0;
	char c=getchar();
	while(c<'0'||c>'9') c=getchar();
	while(c>='0'&&c<='9')
	{
		x=(x<<1)+(x<<3)+c-'0';
		c=getchar();
	}
} 
bool com(node aa,node bb)
{
	return aa.m>bb.m;
}
int main()
{
    read(n);read(k);
    for(int i=1;i<=n;i++)
    	read(a[i].s);
    for(int i=1;i<=n;i++)
    	read(a[i].b);
    for(int i=1;i<=n;i++)
        a[i].m=(double)a[i].s/a[i].b;
	sort(a+1,a+1+n,com);
	if(k==1)
	printf("%.2f\n",a[1].m);
	//if(k==n)
	//printf(".2f\n",a[n].m);
	return 0; 
}