import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] sa = br.readLine().split(" ");
		int n = Integer.parseInt(sa[0]);
		int s = Integer.parseInt(sa[1]);
		long b = Integer.parseInt(sa[2]);
		sa = br.readLine().split(" ");
		int[] h = new int[n];
		for (int i = 0; i < n; i++) {
			h[i] = Integer.parseInt(sa[i]);
		}
		br.close();

		long sb = s * b;
		for (int i = 1; i < n; i++) {
			if (h[i - 1] + sb < h[i]) {
				System.out.println("No");
				return;
			}
		}
		System.out.println("Yes");
	}
}