Nature tends to produce constancy in all her works, but she does not always succeed.

We are here to add what we can you to life，not to get what we can from it.

让我们感谢那些使我们快乐的人，他们是让我们的灵魂绽放的迷人园丁。

The beauty of computational complexity lies in its ability to classify problems based on their inherent difficulty.