I am going to submit my initial offer now.
ok
So I really don't need that much firewood. I am willing to give you all 3. What is your situation?
I have a lot of people here.I need food.
I also need food, but am willing to share and give you extra firewood so you can cook more food. I am not able to hunt or fish and the extra food will help if I am not able to get around. 
I can share water for firewood.
Optimally, I would like 3 food and 2 water which would leave you with 0 food, 1 water and 3 firewood. I think it will be easier if you also tell me your optimal wants then we can go from there.
We could each keep 3 food.
No, that won't work. There is only 3 total of food, water and firewood each.
oops I forgot-2 food for you 1 for me