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 C# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;
using System.Collections.Generic;

public class Hello{
    public static void Main(){
        var input = Console.ReadLine().Split(' ');
        var product = Console.ReadLine().Split(' ');
        var answer = "";
        List<int> voteList = new List<int>();
        int total = 0;
        
        for(var i = 0; i < int.Parse(input[0]);i++){
            total += int.Parse(product[i]);
            voteList.Add(int.Parse(product[i]));
        }
        voteList.Sort((a, b) => b - a);
        
        if(voteList[int.Parse(input[1]) -1] >= total / 4 / int.Parse(input[1])){
            answer = "Yes";
        }else{
            answer = "No";
        }
        
        Console.WriteLine(answer);
    }
}