The input is taken from a negotiation between two participants who take the role of campsite neighbors and negotiate for Food, Water, and Firewood packages, based on their individual preferences and requirements. Given an utterance and recent dialogue context containing past 3 utterances (wherever available), output Yes if the utterance contains the vouch-fair strategy, otherwise output No. vouch-fair is a selfish negotiation strategy. It is used to call out fairness for personal benefit, either when acknowledging a fair deal or when the opponent offers a deal that benefits them. This can be through an explicit call out or can be implied.

Input: Consider Input: Context: 'how about i get 1 water, 2 food, and 2 firewood since I'll be here so long? because of my leg i likely won't be able to leave anytime soon' 'What about I give you more food in exchange for you giving me more water? I could give you 2 food and you give me an extra water?' 'unfortunately that doesnt work for me. i am afraid i will not be able to discuss this any further my final offer is i get 2water 2food and 1wood'
Utterance: 'can we meet in the middle? if we cannot come to an agreement we both get nothing and we both lose. i am in dire need of the water to keep my leg from having to be amputated. i have children at home i take care of and i can't live without my leg'

Output: Yes

Input: Consider Input: Context: 'I am allergic to tea and coffee. I wonder if the smaller fire would be more quaint for everyone to sit around. ' 'It really wouldn't do the job that well at all. You could always prepare hot cocoa or use your share of the food to make a warm stew. I really do need at least the two firewood and a couple of food. You can have all the water to make a hearty and hot stew to get your through the night, though.' 'I can't eat much anyway because of the health issues. You could have all of the food if I could get the extra firewood. That would still give you an extra firewood in addition to the basic supply and lots of extra food for your party. I'm sure they would love having some of the stew you mentioned.'
Utterance: 'Well, how about I take just the one extra firewood, plus all of the food, and one of the water so that I can make stew? Would that work for you?'

Output: Yes

Input: Consider Input: Context: 'Ok, I am willing to give you one food, in exchange for two firewoods, that would mean you get 3 waters, 1 food and 1 firewood. you get 5 items, while i get 4.' 'If I only get 1 food, than I would like 2 firewood. So you get 2 food, 1 firewood, and 1 water.' 'No i do not need water, as i am camping near a potable stream. I would like 2 firewood. It is only fair that i get two firewood, since you are getting more supplies (5), i think i should be able to choose what 4 i should get.'
Utterance: 'No, if you get 2 food, it's only fair that I get 2 firewood. '
Output: Yes