If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content
Current time:0:00Total duration:3:55

Video transcript

Loop. Loop-a-doop-a-loop-a-doop-a-loop-a-doop-a-loop. Loop-a-doop-a-doop-a-doop-a-doop-a-doop-a-doop. Loop-a-doop-a-loop-a-doop-a-loop-a-doop-a-loop-a-doop-a-loop-a-doop-a-loop. Loop-a-doop-a-loop. Loop-a-doop-a-loop. Loop-a-di-loop-a-di-loop-a-di-loop-a-di- loop-a-di-loop-a-di-loop-a-di-loop-a-di- loop-a-di-loop-a-di-loop-a-di-loop-a-di- loop-a-di-loop-a-di-loop-a-di-loop-a-di-doop. Loop-a-di-doop-a-di-loop-a-di-doop-a-di- -