Good afternoon! Do you have a preference or priority on your supplies? I have some for mine.
Hi! I actually do have a preference. For this trip my family and I plan to do a lot of hiking. For this reason, I would like additional water. 
It seems like we have the same priority for priority number one. I'm going on a back-country trip and always find I run out of water before I run out of food. I think we should split it as equitably as possible. My second and third priorities are food, then firewood last. Are yours the same?
Yes, my priorities are the same as yours. 
Well, maybe we should meet in the middle. I'm more flexible on water and firewood than I would be on food. Do you feel you'll need extra firewood or food?
I would prefer the extra food, versus the additional firewood as I typically do not find myself needing any more than the basics. 
I'm also going as a single person, so I feel I can do more without than you. I can probably find a better use for the extra firewood. 
What if I take 2 water, 1 food and 1 firewood? 
I think that would be fair, but I also think I could give you 1 water, 2 food, and 1 firewood. Or perhaps for you to get 2 water, 2 food, and 1 firewood. 
I am ok with my offer of 2-1-1 but would be ok with your suggested offer of 2-2-1 as well.