import java.lang.reflect.Array;
import java.util.Arrays;
import java.util.Scanner;



public class Main {
int n,m,mod;
int[] b;
	public static void main(String[] args){	
		new Main().ans();
	}
	int sum=0;
	private void ans() {
		Scanner sc = new Scanner(System.in);
		n =sc.nextInt();
		b= new int[n];
		for(int i=0;i<n;i++) {
			b[i] =sc.nextInt();
			sum += b[i];
		}
		Arrays.sort(b);//昇順ソート
		//int t = sc.nextInt();
		//for(int i=0;i<t;i++) answer(sc.nextDouble());
		answer(sc.nextInt());
	}
	private void answer(double i) {
		int anstable[] = new int[b.length];
		double kari = (double)(sum/i);
		
				int t = 0;
				double[] mynex =  new double[b.length];
				for(int j = 0; j<b.length;j++){
					anstable[j] = (int)(b[j]/kari);
					mynex[j] = b[j]/(double)(anstable[j]+1);
					t+=anstable[j];
				}
				if(t >=i){
					System.out.println(kari);
				}else{
				Arrays.sort(mynex);
				System.out.println(mynex[(int) (b.length - 1-(i-t-1))]);
				}
			
	}
	
}