Problem:
Score : 200 points

Problem Statement

We have held a popularity poll for N items on sale. Item i received A_i votes.

From these N items, we will select M as popular items. However, we cannot select an item with less than \dfrac{1}{4M} of the total number of votes.

If M popular items can be selected, print Yes; otherwise, print No.

Constraints

1 \leq M \leq N \leq 100

1 \leq A_i \leq 1000

A_i are distinct.

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N M
A_1 ... A_N

Output

If M popular items can be selected, print Yes; otherwise, print No.

Sample Input 1

4 1
5 4 2 1

Sample Output 1

Yes

There were 12 votes in total. The most popular item received 5 votes, and we can select it.

Sample Input 2

3 2
380 19 1

Sample Output 2

No

There were 400 votes in total. The second and third most popular items received less than \dfrac{1}{4\times 2} of the total number of votes, so we cannot select them. Thus, we cannot select two popular items.

Sample Input 3

12 3
4 56 78 901 2 345 67 890 123 45 6 789

Sample Output 3

Yes

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.Arrays;
import java.util.Scanner;

class Solver {
    public void Solve() {
        int n = sc.nextInt();
        int m = sc.nextInt();
        int a[] = new int[n];
        long wa = 0;
        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
            wa += a[i];
        }
        Arrays.sort(a);
        double dd = wa * 1.0 / (4.0 * m);
        int cnt = 0;
        for (int i = 0; i < n; i++) {
            if (a[i] >= dd) {
                cnt++;
            } else {

            }
        }
        if (cnt >= m) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }

    }

    Scanner sc;

    Solver(Scanner in) {
        this.sc = in;
    }
}

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Solver s = new Solver(sc);
        s.Solve();
        sc.close();
    }
}