#include<bits/stdc++.h>
using namespace std;
const double q=1e-6;
double a[1000010];
int n,k;
long long ls(double x)
{
    long long sum=0;
    for (int i=1;i<=n;i++)
    sum+=a[i]/x;
    return sum;
}
void ef()
{
    double l=1.0,r=100000000.0,mid,ans;
    while (r-l>=q)
    {
        mid=(l+r)/2.0;
        long long hh=ls(mid);
        if (hh>=k)
        {
            ans=mid;
            l=mid;
        }
        else
        r=mid;
    }
    printf("%.6lf",ans);
}
int main()
{
    cin>>n>>k;
    for (int i=1;i<=n;i++)
    cin>>a[i];
    ef();
    return 0;
}

错了#8，#12和#13