import java.util.*;
import java.io.*;
public class Main{
    public static void main (String [] args){
        Scanner in = new Scanner(System.in);
        int times = in.nextInt();
        int money = in.nextInt();
        int count = 0;
        for ( int i = 1;i<=times;i++){
            if(i%2==0){
                count+=in.nextInt()-1;
            }else{
                count+=in.nextInt();
            }
        }
        if(count>money){
            System.out.println("No");
        }else{
            System.out.println("Yes");
        }
    }
}