Whats the "rule" for all living things?

I think every living things needs to reproduce to survive, so what reproduce mean?

Equation:

Male＋Female＝Different Mass....
Male loses some mass
Female loses some mass
We, makes a new life, a living thing. Unlike the car, that doesn't.

A Car is not a living thing, even if you think it reproduce it self. The mass won't change, they just get some mechanical parts mixed up and stuff

Car A+Car B=Same Mass
The car stays the same, yes. The mass is different, but this doesn't mean they reproduced. They didn't create another living thing.

Another one I think living thing must have is proteins and DNA, because without these. There won't be any difference being a chunck of metal ( Car I mean). Like the car, it doesn't live off proteins and such. It's all identical to each other, there is no difference to each other. Since they were manfactured, there will be a fraud in it, but still humans can fix it.