I'm not sleeping. Doctor said that I am infected by a "slow blink" virus! Each blink takes about 1 hour... 

In order for you to understand Computer better, I shall speak in Computer Binary language: 101000011111..... 

Teacher, you are not very decisive! You said 1 + 3 = 4 yesterday and today, you said 2 + 2 = 4! Can you make up your mind?