Report User Identity Relationship

Good day all.  I ran a report for Inactive Users.  I have a list of almost 3000 users that have never logged in.  I would like to remove these accounts, but my boss wants to make sure that these accounts don't have any other relationships. 

Has anyone created a report that can show me a list of Identities that only have a User relationship and Users that only have an Identity relationship?  Thank you for the help.