How to make a white number inside a black circle (the picture below)? I want to change numbers inside the black circle, of course. I use *Share LaTeX*. I have read some articles here but anyone are not what I would like to get. I would like to get this [an article](https://tex.stackexchange.com/questions/7032/good-way-to-make-textcircled-numbers) (the picture below) - the sixth answer. 

Thanks for help.

[![enter image description here](https://i.stack.imgur.com/4sIor.png)](https://i.stack.imgur.com/4sIor.png)