N, S, B = map(int,input().split())
H = list(map(int,input().split()))

ans = True
p = 0
for i in range(1,N):
	if H[i] - H[p] <= S * B:
		if H[i] > H[p]:
			p = i
	else:
		ans = False
if ans == True:
	print("Yes")
else:
	print("No")