import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Tie tie = new Tie();
        System.out.println(round( tie.result() , 4));
    }

    private static double round(double value, int places) {
        BigDecimal bd = new BigDecimal(Double.toString(value));
        bd = bd.setScale(places, RoundingMode.HALF_UP);
        return bd.doubleValue();
    }
}

class Tie{
    private int number_of_ties, number_of_deputies;
    private int arr_length_tie[];
    private double left_point = 1_000_000_001.0, right_point = 0.0001;

    public Tie() {
        Scanner in = new Scanner(System.in);
        number_of_ties = in.nextInt();
        number_of_deputies = in.nextInt();
        arr_length_tie = new int[number_of_ties];
        for (int i = 0; i < number_of_ties; i++) {
            arr_length_tie[i] = in.nextInt();
        }
    }

    public double result(){
        double middle = 0.0;
        while ( left_point - right_point > 0.0001){
            middle = (left_point + right_point) / 2.0;
            int new_number_of_tie = 0;
            for (int i = 0; i < number_of_ties; i++){
                new_number_of_tie += (int) (arr_length_tie[i] / middle);
            }
            if (new_number_of_tie >= number_of_deputies) right_point = middle;
            else left_point = middle;
        }
        return middle;
    }

}