The hall signs were typed inconsistently. The preceding message demo chained methods; here a notice needs cleanup before a prefix check. replace() returns a new string and startswith() checks the cleaned result.
This is a separate exercise. Edit main.py, press Run to inspect the output, then Submit to check the numbered tasks.
Correct the sign without changing raw_notice.
notice to the stripped, lowercased raw_notice.open_notice to notice with closed replaced by open.is_hall_notice to whether notice starts with hall.