You are a space explorer, who accidentally finds an alien spaceship which seems to be deserted. You, and your team want to get to the control room, but you understand aliens and their technology only partially, so you have to experiment along the way.
When you entered through a hole in the ship's stern, there were no doors or passages. However, there was something eerily similar to what people call transportation pod, and its control panel looked roughly like the following diagram made by one of members of your team:
Of course, the aliens didn't use letters, that just convenience for us, humans. The blue dot denotes the ship's stern room and the red is the room marked with alien pictogram for control room. The yellow and green orbs are buttons.
You didn't know if it would work, but being an adventurous person, you dared to try. You pressed button D▲ and the pod, together with your team moved to room 1, with a small light on the panel acknowledging your new current position.
Well, maybe it does work? You press R▲, but contrary to your expectations, you move to room 2, instead of 3. Now, that's strange, isn't it?
Perhaps, you should've press the R▼ button instead? You do, and indeed the pod moves to room 3. But then, to test your theory, you press B▼ and end up in room 4.
What is going on? Can you find your way (a sequence of button presses) to the control room (you start in room 4)?
Hints for movement mechanics:
If you are in room B, pressing button Q▲ moves you to the very bow of the ship, while pressing Q▼ moves the pod to room S.
If you are in room A, pressing any of the (P,Q,R,S)▼ will take you also to S, and not stern, which also could also seem like a possibility.
In particular, pressing P▼ from room A won't take you to the control room, because you cannot reach it from P going only downwards.
Some clarifications:
- You start in room 4, but if you want to start at stern, that's alright too (in case it is not obvious, pressing D▼ in room 4 will get you to the stern).
- Vertical lines are valid as any other lines.
- It seems that my story is not revealing or constraining enough, so if you are confused, please use hints. My intention was for you to have fun, not get frustrated by an insufficiently described puzzle mechanics.
Edit:
By mistake I've uploaded wrong version of the picture (I have to use several iterations to construct a puzzle). There is small "bridge" which significantly changes the problem (now a solution exists). Sorry for that $\ddot\frown$