import java.util.Scanner;
import java.util.HashMap;
class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		long S = sc.nextInt();
		long B = sc.nextInt();
		int max = sc.nextInt();
		while(--N>0){
			int H = sc.nextInt();
			if(max+S*B<H){
				System.out.println("No");
				return;
			}
			max = Math.max(max,H);
		}
		System.out.println("Yes");
	}
}