It's been so cold these last few days, I'm worried that I didn't bring enough wood for the next few nights.
That is unfortunate. How about I give you are my firewood for all your food?
That is a very generous offer but I think I need to keep some food to be safe. Do you need any water?
I can use water, yes. You could have all the firewood, one food ration. Then I could take the water rations and two food rations. 
Actually, I'd like to keep some water as well in case it gets so cold that the lakes and other water sources freeze.
Well, I need as much food as possible. You seem to want firewood. How about you suggest something.
That's a good idea.Let me think. How about 3 Firewood, 1 Food and 2 waters for me.
That will not work for me at all. 
I see. Then how does 2 Firewood, 1 food and 1 water for me sound? You'll be getting 1, Wood 2 Foods and 1 Water
Your calculations are incorrect. There are 3 firewood, 3 food, and 3 water. You are missing a water. I will return to my original offer since you need firewood the most and I need food the most. I take all the food, you take all the wood. And then you can take 1 water as you just suggested. 
That will work fine with me. Please enjoy your food and two waters.
Thank you, you as well.