n, s, b = map(int, input().split())
h = list(map(int, input().split()))

preh = 0
maxh = 0
ret = "Yes"

for i in h:
	maxh = max(maxh, preh+s*b)
	if maxh < i:
		ret = "No"
		break
	else:
		preh = i

print(ret)