How should I set the upper limit (maximum value) and lower limit (minimum value) for a variable?

Currently, I am using the CLAMP function, but negative values still appear. How can I resolve this issue? Thank you very much, everyone!

This looks fine assuming those events are running all the time, you didn't show the top of the event.

This looks fine assuming those events are running all the time, you didn't show the top of the event.

I fix the problem!!!Thank you!\^o^/