I need help on the last part!!!! "add a new field named Number of Advisees, which counts the number of advisees per advisor." how do I do this part only!!! please and thank you

Query 4 and Report: Create a query that shows the advisors, their departments, and the number of advisees for each advisor. The fields you need to add in this query are Deportment 1D, Deportment Nome, Advisor ID, Advisor Last Nome, Rank, Date Joined, and a new field named Number of Advisees, which counts the number of advisees per advisor. Save this query as Query for Report