Kata

Hey, young man, very glad to see you again in the madhouse, thank you for giving me a lot of help last time.

Now I have a great job, are you interested in?

My colleague myjinxin wanted to find a girlfriend, we as great programmers, what should we do?

I have a good idea, insert ads in the code!

We can do this:

1. when someone converted numbers to a string, 
   we put the advertisement insertion strings inside.
2. But if we do this, ads appear too frequently, 
   we should set a condition, only display ads in prime number

OK, this is my great idea, we can imagine, myjinxin will be able to find a girlfriend very quickly, and soon the wedding, and soon gave birth to a child, is really great!

I have written the advertising text, the rest of the work to you.

Let's get to work!

Crazy programmer series:
        Crazy programmer 01: find SuperMan
        Crazy programmer 02: Insert advertising code
        Crazy programmer 03: Must praise
        Crazy programmer 04: Elephant and fridge