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 Rust (1.15.1) (judge verdict: Accepted)

use std::io::stdin;
fn main() {
    let mut s = String::new();
    stdin().read_line(&mut s).unwrap();
    let (n, m) = {
        let mut sp = s.split_whitespace().map(|x| x.parse::<usize>().unwrap());
        (sp.next().unwrap(), sp.next().unwrap())
    };
    let mut s = String::new();
    stdin().read_line(&mut s).unwrap();
    let a: Vec<_> = s
        .split_whitespace()
        .map(|x| x.parse::<usize>().unwrap())
        .collect();

    let sum: usize = a.iter().sum();
    let line = (sum - 1) / (4 * m) + 1;
    let ok = a.iter().filter(|&&x| x >= line).count();

    if ok >= m {
        println!("Yes");
    } else {
        println!("No");
    }
}