#include <bits/stdc++.h>
using namespace std;
const int N=1e5+10;
int n, m, a[N];

bool check(double x) {
    int total=0;
    for (int i=0; i<n; i++) total+=a[i]/x;
    return total<m;
}

int main() {
    cin>>n>>m;
    for (int i=0; i<n; i++) cin>>a[i];
    double l=0, r=1e9;
    while (r-l>1e-5) {
        double mid=(l+r)/2;
        if (check(mid)) r=mid;
        else l=mid;
    }
    printf("%.2f", l);
}