How to Differentiate CRM and Outlook Appointments using Microsoft Graph API

We are retrieving outlook appointments in our application, but it's includes CRM appointments also. We dont want to view CRM appointments but we are not able to identify the CRM Appointments in the JSON response.

 

We are using following GET api to retrive the outlook appointments:

GET /users/{id | userPrincipalName}/calendarGroup/calendars

Reference: https://developer.microsoft.com/en-us/graph/docs/api-reference/beta/api/user_list_calendars

 

Please suggest us, how can i identify that which is Outlook and which is CRM appointment 

 

Thanks in Advance