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

now_height = H[0]

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

print("Yes")