Office 365 Add Mailbox Permissions

Hi There,

   I have 185 users that I have created in office 365. I got a request today to create 7 New rooms and to give the users full access to 7 mailboxes. I have created a csv file with the mailbox information in a column named mailbox. 

this command is fine if i want to add one user to the 7 mailboxes but how would i do it the other way? How do I add the 185 users to the mailboxes?

“Import-Csv  C:\new.csv | foreach { Add-MailboxPermission  “test@domain.com”  -User  $_.Mailbox  -AccessRights  FullAccess }"