import java.util.Scanner;
public class Test15 {
static int d=0;
	static int kk(int n){
		Scanner sc = new Scanner(System.in);
		int c=0;
		for(int i=0;i<n;i++){
			int s=sc.nextInt();
			c+=s;
		}
		return d=c;
	}

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String s=sc.nextLine();

		String[] s1=s.split(" ");

		int a =Integer.parseInt(s1[0]);
		int b =Integer.parseInt(s1[1]);

		kk(a);

		if(d/a==b){
			System.out.println("YES");
		}else{
			System.out.println("NO");
		}
	}
}