using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static string InputPattern = "InputX";

    static List<string> GetInputList()
    {
        var WillReturn = new List<string>();

        if (InputPattern == "Input1") {
            WillReturn.Add("3 3 12");
            WillReturn.Add("0 10 30");
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("4 1 100");
            WillReturn.Add("0 100 200 0");
        }
        else if (InputPattern == "Input3") {
            WillReturn.Add("10 5 1");
            WillReturn.Add("1 0 0 0 0 0 0 0 0 7");
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    static void Main()
    {
        List<string> InputList = GetInputList();
        long[] wkArr = InputList[0].Split(' ').Select(pX => long.Parse(pX)).ToArray();
        long S = wkArr[1];
        long B = wkArr[2];

        long[] HArr = InputList[1].Split(' ').Select(pX => long.Parse(pX)).ToArray();

        var KaisaList = new List<long>();
        for (long I = 0; I <= HArr.GetUpperBound(0) - 1; I++) {
            KaisaList.Add(HArr[I + 1] - HArr[I]);
        }

        foreach (long EachKaisa in KaisaList) {
            if (EachKaisa - S * B > 0) {
                Console.WriteLine("No");
                return;
            }
        }
        Console.WriteLine("Yes");
    }
}