Anton's Problem
Once there were 3 friends (Anton, Simon, Paul) chatting to each other in a dining hall.
The following happened:
- Anton:
 - I've chosen two natural numbers which are both greater than 1. I'm going to tell Simon the sum and Paul the product of these numbers.
 
- Anton:
 - Now, can you guess the numbers which I have in mind?
 
- Simon:
 - I don't know Anton's numbers.
 - Paul:
 - I don't know them either.
 - Simon:
 - Hey, now I know.
 - Paul:
 - Then I know them too.
 
- Professor:
 - I know Anton's numbers, too!
 
Now, what are Anton's numbers?
