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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
using namespace std;
#define fastio ios_base::sync_with_stdio(0);cin.tie(0);
#define mp make_pair
#define ff first
#define ss second
#define pb push_back
#define eb emplace_back
#define ppb pop_back
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define all(x) x.begin(),x.end()
#define sz(x) (int)x.size()
#define rall(x) x.rbegin(),x.rend()
#define mu(x) x.resize(unique(all(x))-x.begin());
#define srt(x) sort(all(x));
#define sum(x) accumulate(all(x),0ll);
#define rev(x) reverse(all(x));
#define each(x,a) for(auto& x:a)
#define REP(i,a,b) for(int i=a;i<=b;i++)
#define PER(i,a,b) for(int i=a;i>=b;i--)
#define debug(x) cerr<<#x<<" "<<x<<"\n";
#define debug_v(x) { cout<<#x<<"\n";  each(y,x) cout<<y<<" "; cout<<'\n';}
#define debug_vp(x) { cout<<#x<<"\n";  each(y,x) cout<<y.ff<<" "<<y.ss<<'\n'; cout<<'\n';}
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<bool> vb;

int main(){
	fastio;
	int n,m;
	cin>>n>>m;
	vi a(n);
	rep(i,n)cin>>a[i];
	int tot=sum(a);
	int x=tot/(4*m)+(tot%(4*m)!=0);
	srt(a);
	rev(a);
	if(a[m-1]>=x){
		cout<<"Yes";
	} else {
		cout<<"No";
	}
	return 0;
}