RegEx - Not Working with simple rename

I am running into an issue of a simple RegEx rename not working. I highlight the files that I need to rename and then choose scripts - rename using RegEx pattern.

1 - Docuemnt Name - Part
1 - Docuemnt Name - Part
2 - Docuemnt Name - Part
2 - Docuemnt Name - Part

I need to rename the digit and dash at the beginning.

None of the RegEx patterns do anything:

\d\s\-\s
\d -