How many movies had missing values in the 'overview' column before cleaning?

How many movies had missing values in the 'overview' column before cleaning?: a task in SmolDataEnvs-harbor-train-sandbox: 📊 SmolDataEnvs: Harbor (train) (Harbor dataset). Files (in /home/user/input, no subfolders): - tmdb 5000 movies.csv - tmdb 5000 credits.csv