What is the regex match space pattern?

I have the following values for a custom picklist field

1. Lower - L1

2. Upper - L2

3. Side - L3

What is the regex pattern to match the above values?

Mainly this pattern

{anylength of string}{one space}{one hyphen}{one space}{L character}{one digit integer}
I have tried something this way but not working
String message = 'Upper - L2'; String regex = '[a-zA-Z\sL\s\d{1}]*'; Pattern regexPattern = Pattern.compile(regex); Matcher regexMatcher = regexPattern.matcher(message); if(regexMatcher.matches() == true) { System.debug('Matched'); }