I have done this before in another version of this game but for the life of me cannot see how to get to a single output from all of the components I have placed on the screen.
It does look cool but without more directions or hints I am done for.
My advice is to treat it like a puzzle: "how do you implement NAND in relays _if_ you can not do any parallel connections". When formulated this way, it is pretty easy to solve.
(The relays disappear in level 2 and we switch to digital logic, so "cannot parallel outputs" limitation makes much more sense there. I am guessing they didn't want to make up a new mechanic just for a single level, but I wished they'd explain it better)
May I ask how you would have preferred to solve the first level if the game didn't have limitations?
(In real life, I might put a diode OR + single relay-based inverter, but that's too far into analog logic for the essentially digital game)
I found this[0], which is nice in that it's interactive (you can click the inputs to change their values and see how the current flows), though I think the visuals are a little harder to understand. Would be nicer if it had clearer delineation of the relays, and their inputs and outputs labeled with more than just their voltages.
[0] https://everycircuit.com/circuit/4954026060021760/relay-base...
That should be a clue that you're up the wrong alley. A single output means a single output...
(or a 3-state buffer, but I don't think that'll appear in the game)
One of the relays gives you "A and B". The other gives you "A and not B". "A and not B" with A = 1 is just "not B".