How can I set the value of cell in Google sheet with specific length according to the row No? [closed]

I have a field "WorkerID". I want to make it auto-generated as its value populated with every new record. Its format is:

• Length is 5.
• Started with "W".
• The last letter should be digits with the same value = row value.

For example:Row no 1, WorkerID ="W0001"Row no 7, WorkerID ="W0007"Row no 25, WorkerID ="W0025"...