#include"stdio.h"
int main()
{
    int i,j,k,n,m,a[100],t=0;
    scanf("%d %d",&n,&m);
    //printf("%d %d\n",n,m);
    for(i=0;i<n;i++)
    {
        scanf("%d",&a[i]);
        //printf("%d\n",a[i]);
        t=t+a[i];
    }
    //printf("%d",a[m-1]);



    if(t<a[m-1]*4*m)
        printf("Yes");
    else
        printf("No");

    return 0;
}
