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.Collections;
import java.util.PriorityQueue;
import java.util.Scanner;

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

		// 入力値の取得
		int N = sc.nextInt();
		int M = sc.nextInt();
		
		double sum = 0;
		PriorityQueue<Integer> pq = new PriorityQueue<> (Collections.reverseOrder());
		
		for (int i = 0; i < N; i++) {
			int Ai = sc.nextInt();
			sum += Ai;
			pq.add(Ai);
		}
		
		double threshold = sum / (4 * M);
		
		boolean result = true;
		for (int i = 0; i < M; i++) {
			if (pq.poll() < threshold) {
				result = false;
				break;
			}
		}
		// 結果の出力
		System.out.println(result?"Yes":"No");

		sc.close();
	}

}