WSQ13 - Babylonian method

Hello there, this WSQ was an easy one; howhever, it was useful to research a bit from this page about the baylonian method http://mathlesstraveled.com/2009/05/18/square-roots-with-pencil-and-paper-the-babylonian-method/
Here is the complete formula of the babylonian method, you just have to do it on code. EZPZ
 Here is my program working:

If you want to see my code is on this link on Github:
https://github.com/Jocapear/TC1014/blob/master/WSQ13.py