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

now_height = H[0]

for i in range(1, N):
    if now_height <= H[i]:
        pass
    elif now_height + B * S <= H[i]:
        now_height = H[i]
    else:
        print("No")
        exit()

print("Yes")