#include <bits/stdc++.h>
using namespace std;
int n,k;
double a[100010];
double ans;
bool check(int x)
{
	int sum = 0;
	for(int i = 1;i <= n;i++)
	{
		sum += a[i] / x;
	}
	return sum >= k;
}
int main()
{
	cin >> n >> k;
	for(int i = 1;i <= n;i++)
	{
		cin >> a[i];
	}
	sort(a+1,a+n+1);
	int l = 0,r = 0x3f3f3f3f;
	while(l < r)
	{
		int mid = (l + r) / 2;
		if(check(mid))
		{
			ans = mid;
			l = mid + 1;
		}
		else
		{
			r = mid;
		}
	}
	printf("%.2f",ans);
	return 0;
}