//浮点数二分的模板应用

#include <iostream>
#include <algorithm>

using namespace std;

const int N = 100010;

int num[N];
int n,m;
int res;

bool check(double mid,int m){
    res = 0;
    for(int i=0;i<n;i++){
        res += num[i]/mid;
    }

    return res >= m;
}

int main(){

    cin >> n >> m;
    int maxL;
    for(int i=0;i<n;i++){
        scanf("%d",&num[i]);
        maxL = max(maxL,num[i]);
    }
    double l = 0, r = maxL;
    while(r - l > 1e-3){  //注意此处判定条件
        double mid = (l+r)/2;
        if(check(mid,m)){
            l = mid;
        }else{
            r = mid;   //浮点数二分，无需r = mid + 1
        }
    }

    printf("%.2f",l);

    return 0;
}