Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Not the easiest

This stopwatch has an amazing array of functions but is difficult to use; sometimes it behaves erratically and starts timing up instead of counting down, or starts all over again when the countdown is only half done. Don't know if it's really misbehaving or it's just on some obscure other function when I think I set it for countdown...? Operating manual is available online pdf, and it's several pages long.