Just moved in- need your audio knowledge and expertise!

I have just moved into an apartment, and the previous resident has left some in buit surround sound speaks in the living room and also in another room.

Apparently they still work, however there is just a bunch of unconnected wires.

I want to know what do I need to get it back up and running- hopefully as cost effective as possible?

Pictures of the wires and speakers below:

 

Let's assume each wire pair goes to one loudspeaker. You can identify which wire goes to which ''speaker using a 1.5v battery. Touch the battery terminals to the wires, doesn't matter which way round, and see which loudspeaker crackles.
Once you have identified which 'speaker is which, you can use them with your amplifier/receiver or whatever. You will have to maintain polarity, so make sure the wire that goes to the + terminal on the loudspeaker goes to the red + terminal on your amplifier. You should be able to do this at no cost other than time.

S