#include<bits/stdc++.h>
using namespace std;
int a,b,answer,rope[10001];
bool find(int x)
{
	answer=0;
	for(int i=0;i<a;i++)answer+=rope[i]/x;
	return answer>=b;
}
int main()
{
	int l=0,r=100000000,mid;
	double c;
	cin>>a>>b;
	for(int i=0;i<a;i++)
	{
		cin>>c;
		rope[i]=c*100;
	}	
	while(l<=r)
	{
		mid=(l+r)/2;
		if(mid==0) break;
		if(find(mid)) l=mid+1;
		else r=mid-1;
	}
	printf("%0.2lf",r/100*1.0);
	return 0;
}