select query assistance

Querying a table that has the line items for a ticket sold at a retail store.
So I am looking for the tickets that only have CIGARETTE items on it. The
ITEM table has columns:

TICKET NUM (PK)
TICKET_DATE (PK)
LINE # (PK)
ITEMDESC
ITEM UPC
ITEM DEPARTMENT (When equal to 2 then cigarette)

So I want tickets that ONLY have cigarette items (all items on the tickets
are cigarettes no matter the ITEM count.)

Thanks for any help.
.