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)

pub struct Scanner{
    line : Vec<String> ,
    idx : usize
}

#[allow(dead_code)]
impl  Scanner{
   fn new() -> Scanner{
       return Scanner{ line: vec![], idx : 0}
   }
   fn next<T: std::str::FromStr> (&mut self) -> T{
       if self.idx == self.line.len() {
           let mut buffer = String::new();
           std::io::stdin().read_line(&mut buffer).ok();

           let a : Vec<&str>  = buffer.trim().split(' ').collect();
           self.line = a.iter().map(|&s| String::from(s)).collect();
           self.idx = 0;
       }
       let ret : T = self.line[self.idx].parse::<T>().ok().expect("Parse error.");
       self.idx += 1;
       ret
   }
   fn next_string(&mut self) -> Vec<char> {
       let s : String = self.next();
       return s.chars().collect::<Vec<char>>();
   }
   fn next_vec<T: std::str::FromStr>  (&mut self, n: usize) -> Vec<T>{
       let mut v : Vec<T>= Vec::with_capacity(n);
       for _i in 0..n {
           v.push(self.next());
       }
       v
   }
}


fn main() {
    let mut scan = Scanner::new();
    let n:i32  = scan.next();
    let m:i32  = scan.next();
    let a:Vec<i32>  = scan.next_vec(n as usize);

    let mut s: i32 = 0;
    for x in a.iter() {
        s += *x;
    }
    let mut c : i32 = 0;
    for x in a.iter() {
        if x*4*m >= s{
            c += 1;
        }
    }
    if c >= m {
        println!("Yes");
    }else{
        println!("No");
    }
}