I am learning about gates, circuit diagrams ect and I have been asked to create a 3 input NOR gate from NAND gates with 2 inputs.

Well, I know how to create a normal NOR gate with NAND gates, but I just cant seem to grasp how I would get the 3rd input.

So the NOR with NANDS would be:

I didn't just look that up but I cant really draw my own, but I understand how that works, and I checked it with the truth tables and with some inputs.

How would I now create a similar circuit but for a 3 input NOR gate, I don't even know where to start.