user: Question: How many destinations have a Weekly frequency and are named AC Express?
Columns: ['Train No.', 'Train Name', 'Destination', 'Category', 'Frequency']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['11013/11014', 'Kurla Express', 'Lokmanya Tilak (T) Mumbai', 'Express', 'Daily']
SQL:

assistant: SELECT COUNT("Destination") FROM "Table" WHERE "Frequency" = 'Weekly' AND "Train Name" = 'AC Express';