The expression \w will match any word character. 
Word characters include alphanumeric characters (-, - and -) and underscores (_).

\W matches any non-word character. 
Non-word characters include characters other than alphanumeric characters (-, - and -) and underscore (_).
 
Task
You have a test string . Your task is to match the pattern  
Here  denotes any word character and  denotes any non-word character.
Note
This is a regex only challenge. You are not required to write any code. 
You only have to fill the regex pattern in the blank (_________).